Re: she says she likes me but she isn't over her ex-bf!
Does she have any fear of losing you? Was this just thoughts she just randomly through out there? Did she say she wanted a break from the relationship?
Are you bold enough to dor reverse psychology? Thats one move i immediately thought of. Its similar to some other concepts as being confident enough that she will never have anyone better than you--and close to the framing of painting the idea hiw perfect they might be together. This would only really work in your favor if you read some of the previous popular threads about 'do you really want to get back together with your ex'. You might have to search the forums but its there. On top of that you'd have to specifically highlight why they broke up and how thats a positive hidden with the intention that its actually pretty much a bad idea to go backwards.
If he cheated on her and you know this tell her that maybe he really is a loyal guy. If they broke up cuz he sat on his butt all day then say something along the lines of that he might be a really hard worker. It's a complicated move so i wouldnt recommend it to anyone unless they had some strong solid game.
Ultimately my best advice is that in a relationship you only truly deserve someone if you're willing to let them be happy. This is also alart of the idea though that they only deserve to be with you if theybare afraid of losing you. Maybe risk the relationship to only kill thise thoughts she has. This advice is similar to the above but i think its along the right path. You have to give her the option to dispell the notion of ever going back to him by presenting the facts in the most positive way that doesn't ruin your chances of lowering your value as a better choice. In addition you should consider keeping a stronger preselection game.
I'd like to remind you that if you truly believe that your are a catch letting her fail not only gives you the moral high ground but also says you have every right to choose as much as she does. If you're afraid to lose her then those feelings are strong reminders that as much as you could lose her more than likely you can lose yourself in the relationship. By this i mean trying to keep her with you and doing everything you can comes across as needy. Build that Tension that needs to be there to remind her that she needs to commit to the relationship if she's debating on going away.
Every moment counts, get out of your head and enjoy it.