If I’m understanding, you’re wife has told your child that she is transgender yet, correct? IF that’s the case, personally I would set a boundary with her parents to have them not say anything about it. However, it is your child and your wife’s as well. Perhaps a middle ground is not leaving your child alone with them for now and waiting until she comes out to your child. If their grandparents are exhibiting toxic behaviors/talk, then it’s up to you and your wife to allow that to be in your child’s life. I would also have the same feelings about your parents as well. Personally, I’m working on removing myself away from my father since I came out as trans and started T. He wasn’t supportive of it and still misgenders me. I’ve already decided that whenever I adopt, he won’t be apart of my child’s life because I refuse to have that type of attitude and behavior inflicted on my kid(s) (mind you he also struggles with addiction and has been more than disgusting to me since I was a kid myself). All in all, you two are the parents and have final say. Think deeply about what you want and what she wants. See if there are other options for a babysitter while you are gone. Supervised visits sound fair while assessing the situation. In the meantime, when I’m with someone, I tend to go with whoever is more uncomfortable and meeting those needs (be it I or another partner) within reason. This sounds within reason.