A second chance

So my ex calls me. I have quite a history with this woman. She says she's been trying to get in touch with me for two months and I've tried to ignore her but she has been so determined I decided she would be allowed to say what she wanted to say.
So she apologizes for being this and that. I tell her exactly why I couldn't handle her. She agrees on everything I say and says I did right all the time, she think I did what was right et c.
Then she tells me she has changed, that the past months have made her realize what an awful person she used to be and explains it by her medication, which, when I look it up later produces some of her then behavior.
So she asks if I want to speak to her again or if we'll hang up now and never speak. I do however believe that people can change, and that everyone deserves a second chance, so I say let's see what happens but I'm not agreeing or promising anything beyond this. She says it's fine and that I made her day.
I tell her I am skeptical, don't believe it but she says it's okay, she'll show me and that I shouldn't make up my mind about her till I see her again. "See you?" I say, considering it a bold idea considering our past. She says we should meet eventually. I say that it's a decision for the future and we agree on that.

So later that day she tells me how happy and good she feels knowing we speak to each other again and she contacts me the next morning to tell me "good morning". We talk a lot on the phone. It's nice. She shows quite some interest in me, and it's good.

Well, eventually she gets busy with other stuff, work, and doesn't speak to me as often or at all. It's been two weeks now since we tried patching up our friendship, to begin with, made no further commitments. Just last week she made it clear she had no desire to see me as we always "create a mess". It suits me fine, she was the one with the burden of proof.

I have wanted to have a long and serious conversation with her. What made me consider speaking to her more that first call was that I was actually able to criticize her and she took the criticism like an adult person. Didn't give me kneejerk replies and got insulting. I thought maybe she has actually changed, become a more emotionally stable person.
Now, ironically, later that week she first told me that I would have to make up to her all the talk to my friends about her. I was rather upset after her behavior last time we met and my closest friends know about it. This statement was interesting considering how she acted the week before.
Also, she said "now who's a control freak?" a few days later as a return on what I'd told her the first time on the phone, when I was totally honest about what I felt. So her ability to take criticism is still not what I expect from an adult. That comment, no matter how true it was, was still something she couldn't handle and that annoyed and/or hurt her for some reason.

Well, anyway, here we are and she hasn't made any major attempt to contact me for the past four-five days or so. I know she works night shift at the hospital and basically works, eats and sleeps but still. I sent a text, she made a one word reply. I am not trying to contact her, it's all on her now, it's up to her to show that she has changed and to have me reconsider my position. I am not exactly impressed by her efforts. I am not growing fonder of her for not speaking to me.

Either way, and no matter how stupid this situation is, she needs me for some reason. And I feel good with her, I miss her, and I need her but I realized how destructive it was to me so I cut it all, and I can do it again, and I am considering it. I sincerely hoped she could prove that she was prepared to work with me to achieve something, that she had changed, that she could listen to some of what I had to say, I just don't know how much of my patience she deserves and whether I should wait deciding until we can talk all this over and I better know what she intends.