Spears plays both ends; espousing virginity, then acting like a slut in her concerts (note the Madonna-wannnabe photo with the snake, posted earlier in this thread) and playing up her sexuality for all it's worth, which seems to be many millions. Clever but disingenuous, not that her fans seem to care much.
Brittany Spears is just another in a very long line of male and female pop singers pushing sexuality with every move and every song, and the girls who so admire her and want to emulate her may or may not go on to a self-destructive life but these 'acts' will always be with us, only the names, faces and bodies change from era to era. Parents have to be vigilant and do what they can to steer kids away from this type of sexually-driven entertainment but that's easier said than done in this anything-goes era. With schools pushing 'sex-ed' at grade one parents have an uphill battle against the entertainment media unless they forego TV, VCR's, films and all recorded music as well as magazines. Not likely and hardly possible for most of us.
In the Elvis (mid-50's) and Beatles (mid-60's) eras there was a social stigma connected with overt sexuality, especially in teenage female performers, but that disappeared by the late 60's and it's been a contest of 'Who can be the raunchiest' ever since as the pop music business adopted the ghetto culture in the 90's and every guy now wants to be a 'bro' and the girls seem to want to be 'ho's'. Spears just plays to that unfortunate trend.
Personally, I think that if your 11-year-old makes Spears her idol and wants to emulate her, it's probably too late and to pretend that the media culture has no impact on what young people aspire to is a bit naive. From the Elvis-look sideburns guys sported in the late 50's to the Beatle haircuts and right on through the Madonna era, pop culture has always had an impact in a society where every home has two TV's and kids buy millions and millions of dollars worth of CD's every year. Whether that translates to American pre-teen girls adopting a promiscuous lifestyle or not is arguable, but to claim the pop media and it's 'stars', like Brittany Spears, have no effect on kids is not supported by the evidence all around us.