I really think she is just addicted to this new guy. I really think this is not going to work. One of them will end up dragging the other one down, and that will be that.
Also, I don't understand how they don't have counselors telling them what a bad idea it is for two brand new sober addicts to be together. They need to be working on themselves, or it isn't going to work for either one of their sobriety either.
So yeah. I know this is not what you want to hear, but she is going to be feeling the pain you are feeling soon. Don't forget it.
I was in the hospital having my 6 year old, and I had broken up with my ex, after he destroyed my life. Really. It has been 6 years and I STILL don't have the pieces put together. Anyway, I was in the hospital, crying about how it was the worst day of my life and my dad said, "You know how you feel right now? Don't ever forget it. He will be back and he will do it again."
It has been so long, and I have never forgot it. And he did try to come back but I remembered what my dad said to me. By the way, he is not an addict in any way, shape, or form, but as it turns out, regular people can be a waste of life too.
Anyway, it will get a little easier. Don't take her back when she comes crawling, because she will do it again. One day you will wake up and you will be able to breathe again.