AIBU to think dsis should juts take the answer NO the first time and stop bothering people?

But she’s your sister so why wouldn’t you say what you cooking sis, I’m hungry and heading over.
There must be a back story as to why you have only had your niece a handful of times and acting like this. It’s your niece why wouldn’t you want to spend time with her regularly and have her sleepover every week or so?
But if that’s not what you want to do for whatever reason, since it’s your sister surely you just say it bluntly. Plus ask her when she’s taking your kids etc.
Why can’t people just say what they mean especially to close family?

You keep saying an hour like it’s some big deal. Most people commute over an hour every day.
Yes I think it’s normal to want to spend time with your nieces and nephews whether that be going out for food, cinema or sleep over etc.

You clearly don’t like your sister so why don’t you just tell her what you said to me.

A two hour round trip drive is a big deal to me. There is no way I’d be picking up a niece and dropping her off regularly.

Easy for you to say it’s easy when it’s OP who is doing all the driving, not her sister.

This churlish ‘you clearly don’t like her’ is so unhelpful. I like my siblings just fine, I’m still
not doing 2 hour round hour trip drives for them.

I guess I didn’t make myself clear. No she shouldn’t keep asking and yes if it were me I’d wait and hope for an invite not ask you BUT the way in which you’ve worded your ‘no’ inadvertently invites more requests because you’ve said a particular date doesn’t work rather than shutting it down more generally with a ‘sleepovers are too much’ approach

Because she's got an adult child who still needs care?

I do think that there are askers and not-askers though. I have a friend who's an Asker and she is completely content if you say no.b she's also totally content if you say no, never. But to her asking doesn't assume an answer of yes. So why would there be a problem with asking. Whereas I think for people who tend not to ask the assumption is that if you asked, you really are expecting a yes as an answer. So then when those two sorts of people are interacting with each other, life can get very confusing because they each interpret the other's actions wrongly.

I disagree with you. Your original post said you offered to have her sleep to help sis out, it didn't say only once. Have you actually said to your sis it was a one time thing. I don't think you have judging by the excuses you provide her when saying no. You need to be straight and clear, sorry sis, I love Paula, but overnights just don't work, we can't have her overnight again, so will need to look at other options, maybe look into respite care. She can still come to tea fro time to time but I'll have to let you know when that works with me as the pick up and drop off travel is quite lengthy. Maybe we could meet half way, I bring her and you arrange transport for the pick up

OP, you are not unreasonable to feel aggrieved when your DSis keeps pushing you to have your niece for a sleepover, but you need to be more direct with your sister, and tell her that it’s just too much having niece and DC both with their various difficulties. Decide what you are prepared to do, and let your sister know - so if you’re prepared to have her for tea but not a sleepover, say so. If you don’t want her coming at all, tell your sister that unfortunately, at the moment it’s just too much. Don’t say, ‘I can’t do these dates” because it implies that other dates would be OK. And if you are put out that your sister hasn’t had your daughter round, say something to her. I really don’t understand PP who seem to think you have some sort of responsibility to take your niece or see her regularly - you don’t. Circumstances change as DC get older, and ultimately, OP, it’s up to you how often you see your niece.

Exactly. You said no but then yes when she asked on a different day. Why did a different day make you say yes?

Because she probably can’t been keeping a 5 bar gate like you so it’s never crossed her mind!

This is who she is and she is this way because historically it has trained her that if she behaves in this manner then she will get the outcome she wants.

The thing is, you can’t change her, you can only change you. So when she keeps pushing, internally eye roll or smile to yourself and just think “here she goes again”, but stick to your no. Don’t offer a different date, just no. She has years of this working for her, so it is going to take years for her to learn that this won’t work on you anymore.

It sounds like your sister has developed a thick skin in the course of caring for her daughter. She has learned how to ask for a lot of help, to be fairly insensitive when people say no, and to cajole/manipulate/harass them into giving her a lot of support. Hence why she has an active social life and lots of help with her daughter. You are now the target of the skills she has learned, and she's an expert at it. I can understand why it's difficult for you to say no.

One road forward would be for you to become equally bossy at getting help from your sister. e.g. with getting her to take your daughter occasionally. But, since your sister doesn't drive, you'd probably have to drive your daughter over there and pick her up, so I don't know how helpful that would really be for you.

Sounds like your current plan is the best: reduce contact drastically, stop offering to help in any form (as if you give her an inch she will take a mile) and be very clear that you cannot repeat any of the prior help you have given her.

I think you'll have to be direct with her and just say no and nothing else because if you add anything more soften it she thinks that's a negotiation. I wonder if she is also ND? A lot of women are undiagnosed

I guess I'm not understanding why it has to be you all the time since your sister has an active social life and has a lot of help with the daughter?

This...you did offer originally out of kindness and your sister will keep on so just be firm with her from now on.

She sees you as a pushover because you always give in eventually if she keeps pushing. Be firm and stand your ground otherwise she’ll continue to take the piss.

It's very evident from this thread that you like to beat around the bush and assume that people should automatically know certain things.

Just tell her no more sleepovers. It's really very simple.

My sil was like this. Said she'd have mine in return and when it came to it said they were to much hard work (both sen) so I stopped offering to babysit. There was tears and tantrums from her and even ironically accused me.of not wanting to spend time with my DN but I'm not running a free babysitting service.

but why bother to contact her at all? I mean what does she bring to the party?