I understand that this issue can be seem from purely a social justice perspective; however, what is best for the child needs to come first.
The statement regarding possible confusion is true. The conflict could be damaging. The parents would be faced with an extremely difficult task. They would have to help the child understand the contradictions taught to her by her peers, teachers and parents. If the child were older, I think that it would be easier to explain and dialog with the child about these contradictions in a way that wouldn't cause the child to become angry and bitter towards her peers and teachers. The parents would need to find a way to help the child balance the ideas of the family disagrees, the school and the child’s peers. At the same time helping the child gain a respect for her teachers and make friends with the other students. I am not sure that a 4-year-old is old enough to be in this situation.
I also understand the frustrations of the parents and assume that they are aware of the fact that they can not change the schools teachings. I can’t see the parents being happy with the teaching that the child will be learning. This could also lead to future problems between the parents and the school. It would then be the parents’ responsibility not to let these potentially negative interactions affect the child.
I don’t think that the examples, in the article, for possible rejection are the same as this situation. I am not sure why agnostic or Muslim parents would want their children at a private Catholic school. I also think that the mentioned specific moral beliefs are smaller issues. The parents of a 4-year-old would probably not teach her about abortion, but a 4-year-old will realize that she has two same sex parents and that will surround her every day at school. People will ask her why she has two mommies and she will not understand (the same way I didn’t understand when kids asked why I had two white parents). I would not have wanted to be in a school that taught interracial marriage was wrong nor would I want my parents to put me in this situation. It would have confused me more than the contrasts I was surrounded by already did. (Listen to my "I Believe in Stories" essay to hear about some of the very basics.)
From the given information, I do have to side with the school because the confusion could be damaging to the child; however, if the other school options in the are dangerous or are likely to cause more significant problems for the child, I would change my opinion. I could also be pursuaded if the other schools are significantly worse. But I do believe that the politics and the parents should not be the focus; the child needs to come first. As the child gets into high school a catholic school could be a much better fit. High school is a good time for kids to learn about social justice, finding who they are and to begin fighting for their beliefs.
I would love some responses as to why a 4-year-old would be better off in the situation (not why it is unfair toward the LGBT community, which I agree is is. The same a school rejecting me based on the grounds that I was the product of an interracial marriage). There are a couple possible ideas that I can think of that definitely apply to older kids, but I want to hear them from you.