To think this is really mean spirited and she can afford it?

Yes, you are being "really mean spirited".

You come across as very up yourself, comments such as your sister's "pleading poverty", and to be "genuinely surprised" that people think £1200 is a lot for a week in the UK 🙄

You are clearly financially privileged compared to a lot of people. I wouldn't pay £1200 for a week in the UK either but at least I have the sense to realise that that is too much for some, and not others, and to be respectful of everyone's circumstances being different.

You need to back off and leave your sister alone.

She doesnt owe your kids her presence or her DDs at her expense

People who flake are annoying so I understand being a bit pissed off however spending £1200 on a self catering week in the UK is crazy! We only spent £100 more than that on a week in Crete last October. And the idea of spending £4k for a two week uk based holiday blows my tiny mind…

£1k+ for a week uk holiday is bloody criminal

why not?

You really haven't a clue though. You've no idea if her actual outgoings or income after tax and pension etc. You look on paper at a figure and make an assumption.

Plus it isn't just £1200 (which is a lot for a week in the UK) it's also the costs when you are there.

For what it's worth, I'm going to be a single parent soon and my 60k salary is going to be a squeeze - I won't be entitled to child benefit or any universal credit (not saying I should be) and I am acutely aware that I only have myself to rely on. I don't have a second income. If I lose my job, I only have my savings.

people are allowed to change their minds, its not a big deal. You still get to go on holiday.

Would you want your child to spend a week under the care of this OP? I wouldn’t

Can’t you take your niece?

How old is niece? That's effectively an £80k wage which wouldn't go far if paying nursery, mortgage, student loans, etc.

If I had £1200 to spend on a holiday for me and a child, nothing would persuade me to stay in the UK. She could go somewhere hot and interesting for that much. But you don’t know details of her financial situation and maybe she can’t easily afford to spend that much on a holiday, or maybe she doesn’t want to spend what might be her only holiday with family.

For you it is - great, but for a lot of single parents (and couples) £1200 is a lot of money.

I wouldn't spend £1200 (+?) for a week in UK for an adult and a child. It sounds insane.

And it's not just £1200... annual leave, spending money, treats, fuel. Easily £1600+.

Shame she said yes but may well have expected she could find a cheap bolthole and decided that everything is too expensive.

Why don't you offer to have niece, as other posters have suggested? Or ask her if it's just not viable in a non confrontational manner. I'm sure your daughters will get over it. Your sister may have looked into the destination and found it not so interesting to drop almost 2k on, including spends/food etc

And it's not just £1200... annual keave, spending money, treats, fuel. Easily £1600+.

Shame she said yes but may well have expected she could find a cheap bolthole and decided that everything is too expensive.

Why don't you offer to have niece, as other posters have suggested? Or ask her if it's just not viable in a non confrontational manner. I'm sure your daughters will get over it. Your sister may have looked into the destination and found it not so interesting to drop almost 2k on, including spends/food etc

She is a better judge of her finances than you are.
It has to be her decision.

I voted YBU because if she says she can't afford it, she can't afford it. She must have other financial priorities. Things change.

It’s her business.

I also don’t understand why you’re that bothered. Your kids will be fine - they’re each with their parents and siblings.

You can all spend lots of quality time together.

Were you hoping for something else from this? Like that the kids would all go off and play to give you peace and quiet? Or is the niece older and of babysitting age? Or even worse were you thinking your sister would babysit to give your and DH time together - after all we all know single parents live to be everyone else’s babysitter 🤔

Have u thought that maybe she’s hoping you’ll just offer to take her daughter with you so she has a week to herself. Had she got a secret man? Or maybe she’s had second thoughts and really doesn’t want to share a holiday. Obviously she shouldn’t have agreed in the first place

But perhaps after pricing it up she felt it was too much.

Perhaps she’s had some other unexpected expenses.

Perhaps she’s decided to be a bit more frugal this year.

YANBU OP, she should have said no from the beginning if she can't afford it, and avoid disappointing the children.

But it’s not up to you to decide what she spends her money on.

Do you not understand that people often say that they can’t afford things, it doesn’t always literally mean they’re down to their last 20 quid, but it’s money that they feel would be better prioritised elsewhere.

Nobody is awful for feeling disappointed.

However, the sister not going doesn't impact on the OP in any material way. It doesn't make her trip more expensive or more difficult.

What does make someone awful is pressuring people to spend money they've said they can't afford to spend and making grass judgements about how they should spend their money.

Agreed, especially for a lone parent - that £1k in maintenance won’t go that far when it’s to compensate a partners income within the household.

Also agree that £1.2k for one week, especially if self catering, is a lot for one person. There’s such a big difference between splitting holidays with a partner versus doing it all on your own.

OP, she doesn’t want to go - your kids will be fine, it’s not mean spirited of her just leave her be.

Maybe she does have debt though, but pretends otherwise. Lots of people keep their financial situation secret and just tell others what they want them to hear. No-one likes bragging that they have no money.