Depends on when she lost it.
A few act of indiscretion on her part before she learned better doesn't mean masturbation is any better an option. He who looks on a woman to lust after her has ALREADY committed adultery with her in his heart. Since Christianity is primarily concerned with heart attitudes, masturbation is a symptom of that attitude.
And yes, I speak from experience. This is not just conjecture. Cyrano?
It's double-standard, "sexist" time and my apologies ahead of time, but...
The God in Gen. made them male and female, only he made them different; with different sexualities and different desires! And men have the higher urges--that's why God gave women a hymen (the only mammal with one), the capability of saying "no" and expected them to be virgins until marriage.