curious While I see your point on this issue, don't you think you are a bit inconsistent in your position?
Jenna does not want her nieces to have sex. That is clear. Lots of parents/guardians feel that way. But she has put them in belts and I don't believe this is a truly mutual decision. Do you? So I think the belting is wrong. You can agree or disagree on that.
Then we have a person coming along and telling her to go ahead even though that person recognizes Jenna does not want this. This endangers the girl's relationship with her guardian. The guardian who said in her second post she has considerable financial control over the girls. Angelina telling her to go ahead is no different that Kaja saying the parents have no say. It's irresponsible. You can't just go ahead and ignore your family without consequences, just because your girlfriends say you should.
I'm assuming, by the way, that this is a real-life situation. Not some kind of academic argument. You can't just do what you want because it's legal.