Ann Wilson has mentioned a few times in interviews that male groupies were a part of the Wilson's lives. It happens..but like ILJP says there just aren't (or weren't..there are a ton of female pop stars out there now) as many female rockers out there.
As far as the underage thing goes, that's just brutal. I had my fill of sex offenders when I worked at a prison and have zero tolerance for anyone who likes to do kids. Odd how society will cry out for the noose to be given for a teacher that screws around with a student, but as soon as a celebrity does it the act is deemed less serious. Bizarre.