Is she over him? Should I worry?

Heya guys, I got a question...

I started seeing this girl about 3 weeks ago.
It's going well, but here is the thing... she broke up with her ex boyfriend about 4 weeks before we started going out. They had been together for one and a half year.
She says she is definitely over him, that the relationship was making her unhappy and that she feels like she was even over him before she broke it off with him.

At first, she told me she wasn't looking for anything serious, but now she is kind of changing.
We kiss whenever we see each other, we cuddle, we get along really well and she is really into me and wants to see me.
I really feel that we are getting closer to each other, and she seems to be a lot more interested now than what she used to be. I get the feeling that she has been changing her mind the past two weeks.
She has introduced me to her family, her friends and so on.

We are both 20 years old and we met at work (her as cashier, me as customer).

Also, I am really into her. I have never found a girl that I share so many interests with.

She has told me that she felt down and sad the first week after she broke up with her ex, but that she feels okay about it now and, like I said, that she is over him, that the relationship was over before she "formally" ended it and that she is much happier now.

Finally... she gives me all of these compliments. Like, how she really appreciates the way I treat her and how she's not used to it. How I'm so thoughtful, how sexy I am, how good I smell and so on. And yes, we have done sexual stuff. Nothing advanced, though.

Well, I'm just kind of worried... she hasn't showed me any signs whatsoever that she is still upset about her ex or anything like that, and she is really in to me, and vice versa.
I have also made it clear to her that I won't let her hurt my feelings and I have made her promise me that I'm not some rebound thing and that she really IS over him.

The last time we were together I told her I would probably be worrying about her changing her mind about us. But she assured me that I had nothing to worry about and that she really wanted to keep seeing me.

My question is simple. Should I worry?
Be brutally honest, but please don't crush my hopes unless you are 100% sure it won't work out.

I don't think you should worry. She basically explained her situation with you which is good. She was honest. And as long as shes not doing anything suspicious...its all good.

I think, if you don't stop worrying over this, your lack of trust for her may turn into a self-fulfilling prophecy...

Women often leave relationships emotionally long before they do so formally, so you probably shouldn't worry about it too much. Since she was the one who called it off, I am pretty sure she isn't wanting him back, whether or not things work out for the two of you.

You will know she is over him completely when she doesn't spend excessive amounts of time complaining about what a bastard he is. Yes, she will do SOME comparing, but the hostility should diminish with time (unless she is very immature).