You’re her [i]rebound guy[/i]! 😕 She’s suffered a blow in her break up, and you’re the knight in shining armor that’s kindly helped her through this rough time. Since she doesn’t have a boyfriend, and you’re a nice guy who’s a known entity to her, you’re safe — and attractive.
There’s nothing wrong with you asking her out, or dating her, but understand that you may get your heart broken when she realizes one day down the line that dating you was part of her therapy to get over the break up she’s just suffered. People do all sorts of things to avoid pain, and dating you will help her not feel alone, not feel unloved and not feel unsexual.
I hope that helps you make a decision on what to do next. 🙂