Well, you've already acknowledged the huge red flags going off by what she has endured to date. Now...
*deep breath here*
I've been down this road, and it is indeed a heavy burden to accept. The first things I would evaluate would be whether or not she is committed to healing and is actively in therapy to deal with her childhood traumas first off.
Ex eating disorders have a way of becoming current eating disorders that she is hiding, and medical bills, and drama, and stress from you worrying about her health, etc...
Sexual abuse is one of those really difficult to deal with things. One day everything is fine, then she has a drink, you go to hug her, she freaks the hell out, and you spend 45 minutes consoling her. or she steadily develops guilt and additional issues related to not having dealt with the initial abuse. Or she uses it to manipulate you into behaving in a manner that just isn't you because she claims your normal modes of behavior trigger bad reactions in her.
If you're a really nice guy who cares about her, then you should be probably prepared for the point in which she figures out that she's really still hurting, that you treating her well confuses her a lot emotionally, and she'll run away screaming and do things that hurt you.
Of course, none of this could happen and you end up just being a brief rebound relationship too..
"Well, then," the Cat went on, "you see a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad."