IMHO, it is wise to be very guarded and careful how much you reveal at this point. i don't know anything about your past, but since you are posting this here - i assume she was abusive and that is why you have had no contact for a long time. abusers can change, i suppose, but often we survivors hope for change that doesn't happen. please protect yourself. keep yourself safe - both physically and emotionally. don't let her manipulate you into getting whatever she wants at your expense. it is not cold or cruel on your part to do what is right for your own well-being. if she can prove she is owning up to the truth and wants forgiveness or to make amends, that would be great - but it is only natural for you to be cautious and skeptical. BTW - if you feel the need to forgive her - that is also fine - but it doesn't mean that you have to "forget" as well. it should be up to YOU how you proceed.
"the scariest thing about abuse of any shape or form, is, in my opinion, not the abuse itself, but that if it continues it can begin to feel commonplace and eventually acceptable."
- Alan Cumming, "Not My Father's Son"