I hope I'll never find out!
And how should children feel for completely disappointing their parents and going against what the parents believe? It's a two-way street.
The lesbian you speak of must understand that she can choose her immorality but she can't choose other people's response to it. I am sure her parents would welcome her back if she starts living right. They would rejoice, I'll bet you. But they should not have to ignore their beliefs for the relationship. Clearly you do not expect the daughter to ignore her lust for women in order to restore the relationship? Why should the parents have to ignore their principles? It works both ways.
It's one thing if the child is underage, but quite another if they are adults.
I know someone, very conservative, whose (adult) child is homosexual. The parent would love to maintain contact but the child refuses to maintain a relationship solely because of the parent's "homophobia" even though the parent never, ever even brings up the topic.
In fact, other members of the family refuse to speak or write to this person because they are intolerant of "homophobia". Even though the parent in question never, ever mentions anything about homosexuality.
So the shoe can be on the other foot as well.
I do not mean my criticism of the Cheney's to be because they didn't cut her off. I mean it be because they embraced her like it didn't matter. The "cut her off" thing was brought up by you and I think someone else (regarding Alan Keyes). I don't see that as the worst response, though not necessry (Alan did not cut his daughter off, for the record). I see the worst response as total acceptance.
Although I am 100% he-man straight, I know -- in fact, I am very close friends -- with many gay people, both men and women. The response from their parents is as varied as humanity itself. The parents of a lesbian I know are well known in the community as radical leftist socialist pigs (Ok, so I added the "pig" part). When my friend came out to her parents, they stopped paying her college tuition and pretty much shunned her. On the other hand, when a gay friend came out to his parents -- who he calls "Archie and Edith Bunker" -- his father said something like "at least you're not a car thief, and I we won't have to worry about you knocking up the a neighbor." Yes, his parents were disappointed, but he kept they kept things in perspective.