To think she should drop the single parent label in these circumstances?

I think you're underestimating the stress and juggle of getting the child ready and to nursery every morning and then racing off to work. The rush back to pick up, dinner, quality playtime, and bath and bedtime routine on your own after a full day at work. All the laundry and housework around this.

Because when my partner works away it's really hard! It's also hard having to do both nursery runs and often getting in slightly late, and having to worry about getting out on time. I have huge admiration for your sister (and any single parents) managing to juggle this. Sounds like she deserves her time off at the weekends!

I've just finished mat leave and two at home was easier (for me) as I could run to my own schedule. Get things done in the day. Potter about with them and have nice times meeting up with friends. I look at a couple of my friends working and parenting a lot of the week on their own and I'm in awe of them.

She's made her choices and organised her set up to make the best of her situation. Have you done the same? I can't help but think of you were content you wouldn't really be interested in what she called herself. It simply wouldn't occur to you to question it. You might feel irritated but I don't think you should be looking to her for the reason.

Her life sounds brilliant and it's good for her DC to see their parents getting on so well. I am a bit jealous I have to admit.
She is still a single parent and I assume makes all the day to day decisions. If she was living with a partner it would be different but she's not.
Is it more because you feel she's criticizing your parenting? Because anyone would be annoyed at that. Just tell her to mind her own business or point out she has a lot of child free time which you do not.

It's not your sister's fault you are struggling. I'm a SAHM and if I want to get my hair done and meet a friend at the weekend, then that's what I do. Admittedly that was a lot harder when they were babies but the baby stage is a flash in the pan and is over too soon IMO 😪

She's a single parent and still has the physical and mental load of looking after her child alone every morning and evening during the week whether or not they are at nursery.

I am and have been both a lone and a single parent with two children with two different dads. ( one very involved, one completely absent)
Both bring their challenges but for sure being a lone parent is harder (if the other parent is decent of course, if he is not that's a whole other set of problems)

I take huge issue with this line of OP

*and enjoying the weeknights without the stress of being a SAHP.

You very obviously have never had the stress of rushing from work to make pick up, bringing home tired kids, getting dinner on, homework checked, listen to their day, get to extra curricular activities, do bed time etc or some combination of the above depending on age of child or children.
Young kids end up later to bed than those that are home all day and up early next day to be dropped off early so you can rush off to do another day's work and start the cycle again.

Sorry for rant but that sentence just proved to me that you have no clue what you are talking about!

Life can be hard fir people in all situations. Both you and her can find parts of parenting difficult, even if they are different aspects you are struggling with.

But she literally is a single parent. Sure, she has it easier than a lot of single mums, but that doesn't mean she isn't one.

Well I'm assuming she doesn't stick the child in a cupboard between nursery Monday to Friday, so discounting that time on top of working is doing her a huge disservice.

You need to get your own house in order rather than criticise hers. She sounds like a very on top of it single parent who sets boundaries and looks after herself.

Going against the grain here but I am single but co parent very well with my child's dad however I hate the term "single parent"

My relationship status is single but I am most definitely not a single parent.

It's no different if she were super rich and had a nanny to provide childcare, she is still a single parent. Or if she had no money but very involved parents who happily did childcare.

Your issue is your relationship and split of work. If you want time off arrange it as a regular slot, Saturdays are family days and then you and your DH have EOW Sunday child free to spend as you please.

You're baiting for a fight.

Isn't this really just about the distinction between a single parent and a lone parent?

How old are your children OP?

I’d say I’m a single parent. Work full time. ex has them half the time. I am single though and a parent. I think lone parent is when you have all the responsibility. We do coparent but I wouldn’t say I am a coparent

I don’t think it’s necessarily easy working with young children. You sound jealous tbh If you’d like to not have the stress of being a sahp then get a job?

This. Maybe she'd like to be a SAHM but can't.

Well she is a single parent and she has found ways to manage it, so I can't see anything she is claiming is false.

She might be able to have more freedom than you at the weekend, but maybe there are aspects of your life she finds enviable too.

Parenting shouldn't be a battle about who has it harder, it's just about making the right choices for you and your family. You have chose a different and perfectly valid path, she has had her hand forced because of a relationship breakdown, but is making the best of it that she can in a way that works for her.

Yabu

She's single and a parent. Literally the definition.

You have the luxury of a partner to share the load, mental or physical. She doesn't. There's no need to be jealous.

She’s a single parent with a more favourable set up than a lot of women. It’s still not ideal and with this kind of set up problems tend to arise further down the line when new partners come into the mix and when the kids are older/ become teens and start picking and choosing which house they want to go to and playing parents off against each other. Does that make you feel any better?

She's single, she's a parent so she is a single parent. Sounds like her and her ex co-parent very well too. Instead of griping about her start organising your own self care time, if your sister's ex can manage that much childcare so can your husband!

On a dating app I don't want to meet anyone with kids. If I say "no single parents" meet someone, and then they drop the bombshell on me they have kids I'd be furious. If they then justified it by saying they "co-parent their children so aren't a single parent" everyone would think they were completely batshit, because the very definition of single parent is someone who is a parent but isn't in a relationship!!

I’d hate to be away from my kids every weekend. Is that really what you’re jealous of?

I'm separated from my exH, he has the dc half the time so I have never considered myself a single parent. So yes, I agree with you. I think if the children's father is very involved in the co-parenting, the mum isn't a single parent. They might be single, and a parent but they are not parenting solo.

She is a single parent. Literally the dictionary definition.

She is not with her child’a father thus, is a single parent.