What SparkleKitty said. You can't predict her failure just because she doesn't want a relationship with you at this point. She may have very good supports in place with her recovery program. If she does fail, it's on her. If she succeeds, it's on her (and it would be, even if you were there).
I think we have to be every bit as careful about taking credit for someone else's recovery as we do blaming ourselves for their failures.
What about YOU, ch? It seems to me you might want to examine your need to be the hero, here. I'm not discounting the sense of loss and grief that come with a breakup. But reading between the lines, I get the sense that you're very wrapped up in the idea of "saving" this woman and her child.