My sister is behaving like a crazy person

[micapainter]

I am desperate for help. My sister has been behaving strangely since the birth of her son last year. It all started with my dad and how she cut him off over a silly argument they had because he didn't call her to congratulate her on the pregnancy. I now feel sorry for him as she has now been treating the rest of our family the same. Twisting things that have been said and saying some really nasty and cruel things to me and my mum. My mum is heartbroken as she now can't see her grandson. My sister has always been quite a volatile character but this pregnancy seems to have turned her into a monster. We have not been nasty to her but she takes tiny things we say the wrong way and sees things that aren;t there. I tried to gently broach the topic of her emotions and possible pnd but she flew at me and has now blocked be and my mum on Facebook. She returns my mum's presents saying they aren't to her taste and not what she asked for. My Aunt sent her a card but my sister told her she is a great Aunt not just aunt, really petty things. My mum has tried to get in touch with her husband and in-laws but they ignore her messages and then go straight to my sister which then makes things worse as she attacks my mum for going behind her back.
I was just reading another post from a concerned sister and she described her behaviour the same. If my sister won't seek help or admit there is anything wrong with her what can be done? I have told my mum to give her space and maybe she will calm down? It has been 10 months since my sister gave birth. I have tried every approach possible with my sister but you'd be shocked at some of the things she has said. It feels like she is deliberately pushing us away and she always likes to play the victim.
My mum is going to cut her out of her will if things don't improve by the end of the year. i'd also be fine not having anything to do with my sister but it's the thought of never seeing my nephew that breaks my heart. I worry about him as she has become very controlling, she even admitted to me that her friends think she has a problem with control. Just wondering if anyone has any experience that is similar or knows how to deal with this personality type? I am starting to think she has a personality disorder.

[User543212345]

You're calling her a crazy person, ignoring her requests and your mum is threatening to cut her out of her will unless she toes the line? Sounds like she's the only sane one and is distancing herself from some toxic family drama tbh. Leave her alone and stop calling her names/undermining her to her in laws.

[Surreyblah]

Sorry you're having difficulties.

First I would stay well out of her issues with other family members and stuff like your mum's will! And focus on your own relationship with her. You can't reasonably expect to have a relationship with your DN without one with your sister.

[Heirhelp]

I agree that it sounds like she is putting distance between herself and her family to protect herself.

If you know who her GP is then you can ring them an explain your concerns.

[myoriginal3]

Why didn't your dad congratulate her? That would have pissed me off. It was like the waltons in the waiting room when I have birth! First grandchild....

[toastymarshmallow]

i'd also be fine not having anything to do with my sister but it's the thought of never seeing my nephew that breaks my heart.

You don't get one without the other. Your nephew is her SON.

You all sound like bullies who expect to be able to say what you like and never be pulled up on it. And if she dares to hold any of you accountable you claim she is making it up/has a personality disorder.

Respect her decision and leave her alone.

[toastymarshmallow]

If you know who her GP is then you can ring them an explain your concerns.

Awful advice. Do not do this.

She has a right to never speak to any of you again. Respect that.

[ILostItInTheEarlyNineties]

All I can suggest is to stop trying to contact her. Perhaps she will eventually get in touch on her terms?

I would have thought that if she was exhibiting signs of a mental illness then the people who see her daily, her husband for example, would encourage her to seek help.

Maybe you could write her a letter explaining that you miss her, would like to see her and build a relationship with your nephew? Don't drag up the past or accuse her of being "crazy", or threaten her with loss of inheritance though! That would be completely counterproductive. Concentrate on your relationship with her first.

[micapainter]

wow I am surprised by the amount of vitriol on here! Maybe I have given the wrong impression but never have we told her she is crazy or mentioned the will or talked nasty about her to anyone, those are things my mum confessed to me in private. I would be more tactful than that! We have been totally kind and supportive but she has been the one being abusive towards everyone in the family. I guess I will seek help elsewhere, hard for strangers to judge when they hear just one side. Thank you for all your comments.

[10Betty10]

Have you got any idea how offensive your post is to people suffering with antenatal or postnatal depression?!!!!!

[10Betty10]

Ps. You aren't being 'tactful' here, so what do you expect?!

[PollytheDolly]

OP. Calm down.

Has she seen anyone about PND? Is she back on the pill? (I only ask this as hormonal contraception had an awful effect on me)

[ILostItInTheEarlyNineties]

I thought I gave some constructive advice .

All you can do is let your sister know you are there for her if she wants to get in touch, perhaps say you are worried she's not been herself? You can't force someone to seek help if they're an adult, even if you do think she's depressed.
All you can do is offer support if she asks for it and if you think her recent behaviour is out of character then don't blame her or suggest she has a personality disorder.

A friendly Email or letter asking her how she is, letting her know you miss her would be a starting point.

[ApplePaltrow21]

You'd be better off posting in AIBU. Everyone here is projecting.

[HyacinthsBucket]

I'd back right off, give her space and let her make contact under her terms. It's awful when your sister seems like a stranger, I'm sadly going through similar but I know that when I'm not trying to contact her, I'm not on the receiving end of her meltdowns. She could be really struggling with her emotions/hormones and coping with a young baby - it's a massive life change - and perhaps is afraid of not being able to hide that from people who know her well? She could also be seeing any well intended help as nothing but criticism if she's feeling low. I'm afraid what you can do is pretty limited, and hopefully if it is PND or similar, then her husband is keeping an eye out. If she's just angry with you all, then let that calm down and try to start on very neutral ground when she does reach out.