The retention rate for Jehovah's Witnesses is the lowest for any religion. If they disqualified elders because their children did not accept the religion they would have very few elders left. I think they used to be more strict about it, but the would have a hard time enforcing it now.
There is a HUGE difference between a child that is gay, and a child who becomes a stripper. Homosexuality is not a choice, but integral to a person. Most gay Jehovah's Witnesses come to terms with this and leave, any that stay live a lie and suffer for it. It's an impossible situation, I pity any JW parent that goes through this, there is no way for them to resolve this according to the dictates of the Watchtower.
Being a stripper is very different. I don't know what would make a young girl want to be a stripper if she had loving parents, and was raised with values and was not sexually abused. If she is an adult there is not much the parents can do about it, although I guess it raises questions about the parenting.