i'm not in a position to make judgments here about this forced/arranged marriage practice of some cultures. but as a friend you can help her with whatever's best for her. if you do decide to help her run away think about the consequences carefully and be responsible enough to face them.

if she ends up running away anyway, it's better that she stay with you where you're sure she will be safe than leave her out, alone, on the streets at night right? and it's also better for her and her parents to stay with you instead of running off to the man she loves.