INFO: Is there a reason you keep saying your money, you paying, etc and not our money, we're paying, etc?

I understand 100% YOU not putting anything into it, and no I don't think your wife should've supported this behavior from the beginning especially since APRIL is her child too, but that's over and done. That can't be fixed now. What can happen is extra resentment to her mom, who I imagine contributed to her sister's wedding but not hers.

Mom should put a little in, still her daughter. I do mean a little. But it's really rubbing me wrong that it's not our money. It sounds like you and your wife consider yourselves separate and not family either between her not having your back with her kid and the way you talk about how YOU pay for everything. It's weird.

NTA, Carly is quite a bit.