Sister is 'uninvited' from wedding, 'she REFUSED a babysitter for my niece.' AITA?

"AITA for 'uninviting' my sister from my wedding because she refused a babysitter for my niece?"

I'm getting married in a few months. My sister, I'll call her Liz, is somewhat of a golden child to our parents but we have a generally decent relationship. Me and my fiance have decided to have a child free wedding - I know many people don't agree with that and that's fine. This is just what works for us.

Liz has a 2 yo daughter I'll call Bella. When I invited her she knew very well it was a child free wedding and asked me still if she could bring Bella. I was polite, but firm in saying no. Liz agreed.

Fast forward to now, she's asked me again if she could bring Bella because she can't find trustworthy sitters and our family members will be at the wedding. I, again, said absolutely not, to which Liz almost threw a tantrum saying I could make an exception for her, and she'll sit close to the door or something if Bella starts acting up.

I offered her some numbers for babysitters that my friends are using but she refused all of them. I got kind of mad said if she's going to be selfish and not be able to leave her child for a few hours, then she doesn't need to come.

Liz got very upset, we had a bit of an argument, but we haven't spoken since then. My friends agree with me but my parents are saying I'm being selfish. AITA?

OP added more context under some of the comments:

My friends are finding sitters and making arrangements - what will I tell them if I make an exception for Bella when they had to go to all this trouble? And my parents are all like "your sister is not a stranger and your fiance's niblings are coming" which I get, but they're older and my friends aren't strangers either. None of the guests are strangers otherwise we wouldn't have invited them.

Yeah I mean I'm upset she won't give up a few hours to attend my wedding, but if she really doesn't want to I'm not going to force her. I've got other guests who can't come because of their kids and that's completely fine - I'm not the type to think an invitation is a summons. But I also expect everyone to respect my rules.

And you don't even know it, our relationship broke down a lot a few years ago when she did something pretty terrible to me (obviously parents took her side then too) but I was open to rebuilding it. Now she's just taking advantage of that.

Here's what people had to say to OP:

Theia222 said:

YTA. I was on your side until your comments about your niblings attending that are 4 and 7 yrs old. Which is an important bit of information to leave out. You have already made an exception for your fiance's family.

You keep hinting at your sister doing something to you, is your niece the result of your sister cheating on an ex? You're allowed to feel betrayed and not invite those you don't want. But don't try and hide behind it being "child free" because your wedding is no longer child free if you've already made an exception.

shwh1963 said:

YTA. You’re letting a 4 yo sibling come but not the 2 yo? You’re doing petty revenge to your sister.

jbyrdfuddly said:

YTA. I didn't think so, until I read down a bit and realized that you weren't having a "child-free" wedding after all. You have every right to exclude your sister, but it does make you the AH (in my opinion). For future reference, being a hypocrite pretty much guarantees that you are the ahole.

Tentacle__Grape said:

ESH you have every right to have a child free wedding but calling her selfish because she doesn't want to leave her kid with a stranger is also AH behavior. Her reaction is AH behavior, your words to behavior was AH behavior.

InstructionCrazy1958 said:

YTA. You are allowing your husband's niblings, ages 4, 7, and 13, plus some 16- and 17-year-olds. You're spiteful and jealous of your sister. It is gross, and I hope your husband realizes the type of narcissist you are.

Misplac3dMuggl3 said:

NTA and I highly doubt she looked for proper child care. Your parents are calling you selfish, and you should say, "I am selfish since it's my wedding." If she can't find a sitter for one day, who's really the selfish one? Changing my vote to YTA. You withheld the whole story. Sounds like you're punishing her for taking the guy.

winter_bluebird said:

YTA because you are NOT ACTUALLY HAVING a child free wedding, you are just excluding your one niece. Your fiance's niblings are invited and they are not much older than her, per your own comments.

You just want to beef with your sister and have strangers on the internet validate you, but you can't even share the actual situation as it is because you KNOW the strangers would call you an ahole. Lol.