Wanting to 'play the role of the savior' is a bit worrisome to me, to be honest. Its a lot like saying that I want to play the role of the winning batter or top of the class; it is a state of being rather than a state of choice.
Anyway, if you want to be there for her, just be there for her. Talk to her, reassure her, and be a friend. Don't expect anything from it; care because you care, not because you want something from it.
This is coming from someone who essentially has a successful 'rescue' relationship: the notion of rescue doesn't last long, no matter how grateful the rescuee is, nor should it, really. It is at best, a pleasant and romantic way to begin a relationship, and nothing more. The rest is the usual connection and compromise, based around something of common ground and commitment.
Oh, and if you're actually interested in her, for God's sake avoid any temptation to ask her to validate you. You do that, you'll be in the friendzone and you can kiss any chances of her actually being interested in you gone.