I would feel pretty comfortable as long as neither can drive and "dates" are time limited and at public locations, etc. Being able to check on her would be nice and, if the boy's family are the drivers, I'd want to meet them (and, presumably they'd want to meet you) at that time. I don't know that I'd let them do much in a group setting with no adult supervision though. If I found out my younger teen daughter was "lying" and hanging out with boys at the Mall or something when she claimed to be with "a" girlfriend, that would upset me. I'd do random spot checks for awhile to make sure she acted responsibly.