Am I overreacting

So yesterday my daughter went to her father’s house (she’s five years old). However, he’s currently dating this female that I really don’t like to be around my child…but I’m working on that. I raised my child to be vegetarian/vegan. She eat eggs cause that’s her favorite at the moment, and I’m keeping some room for her to figure out if that’s what she wants. But no meat what so ever. No chicken, fish, beef, pork, no meat. Anyways she told me when I picked her up just an hour ago that her father’s girlfriend took her to chick fil-a and fed got her nuggets. Which is meat. The father know this, the girlfriend knows this. And when I told both of them they decided to turn the table on me and say that I’m being a bad mother for not properly feeding my child. So now I’m thinking about filing for full custody. I just need advice.