Hook up through kik - Kik Girls: How To Meet Girls On Kik
If you thing your child is responsible enough, I think that 12 is a perfectly fine age to allow your child to have this app. Not sure how to interpret that, but it seems like a step in the right direction. Take off and hang up her coat and ask her if she'd like something to drink or eat. And most of the girls I match with on Tinder arent looking for hook ups, just relationships or something.
Do Not let them download it. Don't look around the room while she's talking; instead, put your phone away, and only break eye contact to smile and look at the ground if things are getting too intense. If she doesn't want you, that's okay -- move on and know you'll find someone else who isn't immune to your charms.
Word of advice: Yik Yak has become the new Tinder - What parents need to know.