I think they're insinuating that this 16-year-old girl is getting unwelcome attention from older men in a way that a 16-year-old boy would not. If I had to guess, I would imagine many of them take the form of "Wow, you're very smart for your age, and very pretty too!"

I'm assuming that they didn't want to go into detail, not that they meant to imply that older people and younger people shouldn't talk.