Well #7 she basically admits openly in a sort of off-handed fashion. As well as could be admitted anyway, since it wasn't known yet that Cloud was being Zack. And why aren't uh... "pure"? people allowed to flirt? I think Aeris's motive most of the time was just to have fun. Like at Gold Saucer? Having fun was probably the best medicine for Berret. Though I'll admit she might have just wanted to have fun herself. I won't presume to speak for her. But it is possible she just wanted him (and probably everyone else) to get his mind off his worries.

It's odd though. I'm a big fan of Rikku. But even I think Rikku is the more juvenile of the two. Of course... she is also a lot younger ^_^