I think it's a slightly different issue, to be honest. Being gay is not something one chooses, one's religion is (or, at least, religion may be something that people absorb via cultural osmosis, but it's not inate).
However, if I were to be a carer, I would accept the rules.
In a wider sense, as a parent, my duty to my child is not to bring her up to believe what I believe, but to give her the ability to think critically enough to appraise the world for herself. While I hope she would think my general views on life were good ones, I don't deceive myself that we will end up thinking the same.