i went to 'sleep overs' where there were boys when i was younger. my parents allowed it. from my own personal experiences i wouldn't let your daughter go. not a lot of sleep going on. and yeah, i had my first kid when i was 17 because my parents let me do whatever i wanted and so i did. not a good idea and yes, at 17 i think every girl should be on birthcontrol because you never know when 'it' will happen for them and it's best to take precautions. preferable something easier than the pill, like nova ring or the needles because the pill is not as effective and easier to miss a dose. good luck and no, you are not over reacting. my daughter(the one i had at 17) never had much of a father and is going into her teen years now. she will certainly not be attending any co-ed sleepover parties.