Don't see what the problem is. Teens are sexually curious. She consented and enjoyed it.
If anything, you should be teaching your daughters to practice safe sex and ensure that she does not get pregnant, lest she becomes yet another abortion or single mother statistic. Put her in a strict regiment of birth control, go visit Planned Parenthood.
Also, advise her to not have sex in public if she can help it, so as not to break public obscenity laws. Get a room.
You parents honestly think your daughters, even those nerdy types and church-going types, are your sweet, innocent princesses who will save their virginity for wedding night? ROTFLMFAO. Oh you have NO idea.
Unless she is grotesquely hideous, she will spread her legs for the next dude who can charm her off her panties. She will get doggystyled in a 'class chalet' or CCA 'meetup'. She will hump like a rabbit in the university dorm. She *may* spread her legs again at work to ensure a good climb up the corporate ladder.
Believe me, I have seen it all. Especially those from all-girls' school; they are some of the most horned up sluts. RGS, MGS, SCGS, NGHS, St Nick's, TKGS etc.