The way that religion connects to the parents' view is easy. "God made you a boy, boys like girls, and that's the end of it." It's probably congruent with the Bible, however misguided in the present that it is.
Possibly, but the Koran has similar assumptions and Iran is the country with the second highest amount of sex change operations (sometimes with public funding) and there it is seen as a way to avoid homosexual relations (better change the boy to a girl, who can then marry a man, than risk gay relations).
In my parents congregation there is a traditional Christian couple that view this in the same way and has supported their "daughter" (ie. self identified son) getting a sex change operation for this reason. So it is not that simple and given the strong anti-gay sentiment of many conservative Christians I find this approach more understandable and better in line with a traditional interpretation of Scripture.
