I tend to agree with you. The mothers in both cases at least seem to care enough about their children to put them in a private christian school. I'm not sure the child should be punished for the parents questionable behavior - maybe they should be ministered to instead of expelled.
Children are always disadvantaged by the poor decisions of the adults in their lives. That's why conservatives preach personal responsibility. If there are no consequences for poor behavior, there are also no incentives to change. Ignoring this mother's dancing wouldn't have helped the daughter and would have exposed dozens of more children to the immorality. Would you want your child exposed to this? Visiting this child's home not knowing the lifestyle of the mother? Other parents in a private Christian school have a right to expect that the families in the school exercise moral, Christian behavior.
My spouse and I do everything we can to protect our children. Our children shouldn't have to be exposed to immorality because other adults make terrible decisions. Our charge is to protect our own children first. If we don't, we're just as foolish as the stripper woman.