Mom issues

Well, my biological mother recently came back into my life after being absent for about 23 years. She was addicted to drugs and my maternal grandparents gained guardianship over me after she neglected me and left me with a stranger. As a child I was willing to forgive her and then she broke my heart as a teenager when she gave birth to my little brother and then lost him due to her selling drugs with him on her hip. A couple months ago I made the decision to contact her to gain a bit of closure. I wanted to forgive her for what she did. I don't want a relationship, but I sense that she does. She keeps bringing up what I was like as an infant and how much she loves me, but I'm having a hard time hearing it because all I can think is that she left me to do drugs and I can't imagine losing my baby for anything.  I do not want to hurt her because in some twisted way I feel responsible for her future happiness, but I just want her to continue being absent from my life, I don't want my little boy to know her and I don't want to keep feeling all of these negative emotions that are attached to her presence. So far we have just texted, but I was wondering if anybody knows how to get rid of a previously absent mother while doing the least amount of damage.