Its becoming more common for girls to have *** at a younger age. Girls have always matured faster than boys, so its only natural for girls to date guys older than themselves which means they often have *** earlier than their male classmates. In all honesty, if the girl is loyal and doesn't cheat, there is no reason to look down on her for her past. She's obviously a sexual person but if you have real feelings for her and she shares those feelings, you should do your best to look past it.
When it comes to past relations of the male, girls tend to like confident guys which usually means they've had experience in the past. Typically I wouldn't think a woman would care how many girls you've slept with, only whether or not she has a bond with you, be it physical or emotional. The bottom line is gender roles dictates that if a woman has had a lot of partners than she's a ****, while if a man had a lot of partners, he's a stud. This is obviously unfair in general, and if you like the girl it shouldn't matter how many men she has slept with. If she doesn't have any major STD's, its not like it will physically affect you either.