to not invite my sister for Christmas?

Maybe not a sociopath but borderline personality or narcissistic traits
You're framing everything with you at the centre. You've gotten worked up at the idea your eldest child will want to live her own life, not centring you, you're annoyed at the idea of your sister stealing your grief limelight on Xmas day. It can't be 'oh poor mum, pushing through her grief's when your sister is sat there going through the same can it?

This post defeats the purpose of the spirit of Christmas!!! You are actually horrible

Having read few more of the comments, it looks to me as if you have found that you are looking into the abyss of death. You want to hang on to all you have controlled for years and keep it like that because of life. You will need to let go of all you have controlled as your kids will move away and your future Christmasses will change. Will you need your sister there by your side in future? What comes around goes around. How is she feeling after spending five years caring for your mother? I did this myself and it wiped me out. I never did recover. But, I also dumped all the friends and relatives who weren't there for me when I needed them!

OP - You are feeling guilty because you are acting like a cow. Your sister has put her life on hold (including a chance to find a new partner) for nearly 5 years whilst looking after your mum so that you didn't need to help and you don't want to give her a dinner on Christmas day. Maybe you should pay her for all the care that she did and get out of her life so that she can find someone who values her as you clearly don't value her sacrifice.

Let's hope your kids are kinder to each other or in 40 years time it could be one of them left alone at Christmas while their siblings celebrate with their nuclear family only. After all, that's what they'll have seen their own mum do, so it must be okay.

Also your timeline isn't working properly, your dad died a decade ago and that same year your sister's husband left her, yet 6 years ago they went abroad for Christmas together and he's now divorcing her. Has she had more than one husband?

Boundaries and self care is for people who are being used or mistreated. In your case this is not about boundaries- it's just selfishness. You must have a heart of stone.

It's just one day OP. Have a fabulous ly chilled. boxing day with the kids instead. How much of an imposistion can one DSis really be. Do you not get on? Is she a PITA? Drip feed coming?
Invite her to a relaxed buffet type day, or to cook together?
Sorry, but unless drip feed is coming YABU.

@NameChangedforThis3036- I can see why you would name change.

You are practicing self care while not allowing your university age child any autonomy as you won’t allow her to spend Christmas with a boyfriend. You sound smug that with three children you never think you will be alone at Christmas whilst happily not inviting your husbands parents.
This isn’t self care, it’s selfish and controlling.

Probably explains why DSIS did most of the caring if she lived close to their mum.

Great point.

OP clearly feels that any life choice that doesn’t include having kids is unimportant.

This is such a madness, when my mum was dying I was rushing home on ferries and planes, my sister who lived closer was the one doing day to day the half the week I wasn't there, we juggled every hospital visit and appt between us. If one of my other siblings complained about the few times they had to do an appt or their small areas of input if lose my shit. Do you hear yourself.

Imagine if instead of the occasional scary spot you did 90% of the appts? And your only sibling couldn't do it because she had ADULT children?! Do you work op? Does she? It sounds like she will have had work commitments at the very least. If you're a sahm to adult children then YOU had more time and availability just less care.

You don't think you are responsible for her choices, but you were happy for her to take responsibility for yours for years. If she had said 'right, I'm knackered, I'm having Christmas in the Maldives' would you have been happy to step up and host your mum? Or did she know full well that your mum would be alone, so she couldn't realistically do what she wanted?

She’s already made it clear that her adult daughter’s partner isn’t welcome either.

She will not be ‘allowing’ her children to go elsewhere. Self care very much a one way street in this post.

I think if you like your sister then you have to offer her to come. She may say No and prefer to work or go away on her own and recuperate from what sounds like an awful year for you and her.

Not actually inviting a close bereaved relative at Christmas when you know they’re on their own, is selfish and cruel behaviour and could damage your relationship in the future. If you want a family moment just with the kids - have an evening out in the lead up or between Xmas and NY instead.

Has your sister even said she wants/expects to come to yours for Christmas? You say the last time you all (you, sis, and mother) had Christmas together was 2019; I would not assume anything. FWIW, I was happy and relieved to be able to have Christmas on my own after my mother died, but I felt guilty about feeling that was and attitudes like yours would probably have made me feel (unfairly) like it was inappropriate or offensive to say so. If you have legitimate concern about what your sister might feel or expect, and you care about her on some level, then just talk to her rather than catastrophising.

OP you do realise there’s a difference between self-care and utterly selfish?

I haven’t read such a self-centred uncaring thread for a very long time.

And by the way my DC are a similar age with long term partners, and they have always spent Xmas with their respective families.

There's a pattern here that you leave everything to someone else and see no responsibility to anyone except your 'nuclear' family.

Christmas is over 3 months away your eldest could still decide to go elsewhere. Your younger two could decide to stay at uni or do something else.

Your sister literally put her life on hold to give personal care to your mum in her final years/months and you can't give her a seat at your table for one afternoon.

You've not told your DC yet, are you worried they will think you heartless? If they don't you will have Christmas in the future alone.

It depends what kind of a relationship you have with her. If you have both been very close forever, then I would invite her. If you want to set a precedent to keep her at arm's length forever, you don't invite her. The choice is yours. Put yourself in her shoes and ask what you would like to hear from your sister depending on the kind of relationship you have. Does she have close friends? How much of the more caring did she do? Does she work full time and have a good social life? Or, is she completely alone. Will she become emotionally dependent on you in the future? Please weigh all these questions up. You could of course say that you are so exhausted that you are having a very small Christmas this year, just the lunch, and perhaps invite her on New Year's Day. Remember, you are in the very early days of mourning and will go through a whole myriad of emotions before you even begin to see an form of reality.

In the nicest possible way, I don't think you need to practice self-care at all, you need to practice empathy and putting yourself in other people's shoes... You've spent the last five Christmases alone with your family while your sister has spent them caring for your mum with dementia.
You've been through something awful, no doubt about it... But you seem to be zooming in on that without acknowledging that the fundamentals of your life (working, lovely family house, husband) has remained unchanged, while it sounds like your sister has given up everything (conveniently meaning you haven't had to).

Staggeringly cruel not to invite her.

Woooooow

So you’ve let your sister care for your elderly mother with dementia on her own at Christmas for the last 4/5 years, while you’ve had your own little lovely family Christmas. This year she’ll be on her own and you are seriously considering leaving her because you need another Christmas just to yourself

You come across really selfish - karmas a bitch! Remember that

OK but this is not the time to change that. You know that really or why post about it? Invite your sister. You could say that you understand if she prefers to do something else this year, but make it clear that you all love and value your sister. If you do??

This is a really upsetting read.

This is a woman who has sacrificed large parts of her life to taking on almost all the caring responsibilities with all the misery and exhaustion that comes with end of life care. During that - and maybe partly because of it - the life she thought she would have has fallen apart, leaving her on her own at a time when she most needs support. Her willingness to do this has enabled her closest relative to have the life she wanted, focusing on her nuclear family and doing minimal caring. One of the main reasons she was in a position to do this was her decision not to have children. If she had, then the OP would no doubt have been under considerably more pressure to do her fair share of care, and would not have been able to have Christmases just how she wants them. Now after a year that must have been exhausting, grinding and probably traumatising, the OP wants to exclude her, and is using the very reason she was able to shoulder this burden - her choice to be child free - as one of the justifications for doing so. 'Well it's not my fault she made a perfectly reasonable life choice and then gave up all the advantages that should come with that choice to allow me to do what I liked. She should have planned better even though that would have involved me not getting what I wanted and being under a lot more stress and pressure.'
I'm sure the OP did worry about her mother, but that worry is a tiny thing compared with what her sister must have gone through on a daily basis. I have been involved in end of life care for a short period of time for someone not directly related to me and even those few days were brutal and exhausting. I never, never want to experience that again.
Christmas is an incredibly symbolic time and I think loneliness is almost baked-in to it. People who are perfectly happy living alone and who normally have busy, full lives with friends and wider family can find themselves feeling lonely and sad at Christmas because everything about that day is presented as a time to be with others. If the OP chooses to exclude the person she owes so much to at the very time when she may need more support than ever before, she is, underneath all the 'my precious little family' veneer, a fundamentally selfish and unpleasant person. She can make that choice, but I wonder what her children will be thinking of her deep down, even if they don't voice it.
It's one day, set against all the awful days the sister has experienced so that the OP didn't have to. There's very little nuance to this - it's just a wrong and selfish thing to do to anyone, let alone someone you're supposed to love.

You know it’s only 120 days to Christmas when the threads start on Mumsnet 😂

… they also continue for about 30 days afterwards, fallouts, shit husbands, no presents.