My friends was treated for genital warts and wants to know if she should get the vaccine to help prevent future breakouts, and possible cancer?

Yes: Women under the age of 26, regardless of past contacts, have been shown to benefit from the hpv vaccine.

Can provide help: The vaccine does not undo the earlier infection & is unlikely to change the chances of a recurrence of the earlier warts. It can provide protection against another wart strain & the 2 that are most associated with cancer.