You're not the only one with great teens. I have lots of 'em, too:
Carrie:
Madalynn:
Janine:
Pam:
You might want to get that chick to smile. The teen thing is about innocent, not sultry, and girls are much more appealing when they look like fun.
And you're right about retention. A good teen shot retains much better than an off-the-rack Matrix shot.