It's simple. Try and remember all the things she liked about you. Make sure you give her big doses of nostalgia. The fact that she ignored you for 2 years means you either weren't all that interesting or all that good looking. I've never heard of a woman rejected who actually goes away, unless you guys were "friends" and were always going to be that way. So if she doesn't show interest when you blast her with the "remember whens", then you're probably fukked and creepy. To me, it sounds like you got the situation wrong.