Need your advice - sisters wedding drama

Okay so my sisters wedding is coming up in a couple of months and both my husband and I are in the wedding party. So we had planned to bring a babysitter to help with our 1 year old. I live 5 or so hours from all my family so they see our daughter once every couple months due to work schedules and the distance. So my daughter isn’t too familier with everyone..

Anyway the person we were planning on bringing that my sister said a couple months ago she could come has uninvited my friend whom was going to help. She was uninvited because my sister got jealous that my friend had purchased one of those electric jeeps for my daughters birthday. Apparently my sister wanted to get one for her but nobody knew about it. Btw both my friend and sister are Jeep owners so they’re kind obsessed. So I told my sister I guess my daughter won’t be able to attend because I know my daughter won’t feel comfortable being passed around like a hot potato. My sister told me she knew she was being petty towards my friend but didn’t care. And that she still wants her niece/god daughter (aka my daughter) there. She said That she lost respect for my friend because she got my daughter the Jeep and didn’t bother to message my sister about it. This is so unlike her and not in her character and I feel so disappointed in my sisters childish behaviour. Of course it’s her wedding and she can have whom ever she pleases there but she’s putting her pettiness above my daughters comfort.

In general she has always been jealous of my friend because she is around more. She lives about two hours away from me. I live in Canada and she in the states by the boarder so it’s a bit of a hassle to come around on the weekends when she has time off but she makes the effort. So I obviously appreciate that. Where as my sister doesn’t really make the effort as I believe she rather likes the idea of being around more but not doing anything about it. Instead she always gets mad at me for living far away and mad that my friend is always around and blah blah blah.

I don’t know what to do. I want to be there for my sister. But I’m not willing to compromise my daughters comfort. My friend is the only other person aside from my husband and I that is close to my daughter. She basically acts as an extension of me. She isn’t shy to help any way she can. Bathing and diaper changes included.

My husband and I were thinking maybe he step down from the wedding party so he can take care of her but I know that won’t go over well with my sister 🤷🏻‍♀️