XDH and I split almost 2 years ago, he is Roman Catholic by birth (he comes from South America and is what I call a lax follower, i.e. says the words but doesn't live the life) and I am Atheist.
When we split we agreed he would have her every other weekends, and he has occasionally taken her to church with him duringthese weekends. I didn't really have an issue with this as I was told that she was going to the local Catholic church and I felt that she'll come to her own conclusions when she's old enough.
I've now found out that his mother moved to an Evangelical church some time ago and XDH and DD have been going to these with her instead and it really doesn't sit right with me; from what I can gather from anecdotal evidence and what I've read, it it is just one step to far in the direction of brainwashing for my liking.