I would just give it to her. It's her business who she wants to date. Anyway, she's already 19. No sense holding her back. But because I'm Chinese and am rather traditional (especially since my parents are very traditional), I still want her to at least bring her b/f home for dinner so at least I get to see him and find out at least what kind of person he is before she decides to marry him or something.

But I'm still 18, so I'm not sure if my views would change as I get older.