It seems to me that the Grandmother was a traditional devout christian woman. Though she was far from a saint in the story, often judgemental, the encounter with Misfit was life changing. Not life changing in the event of her demise, but in the sense she came to a realization. I think she finally felt one characteristics of a Christian:compassion. When she states that "The Misfit" is one of her babies, she felt a maternal connection. She felt it could easily be Bailey, performing the same heinous acts. So I think like most mothers, no matter how horrific their child is they see the goodness in them. It was similar to Jesus being hung from the cross asking forgiveness for the sins of man. I dont think it was as significant, but in some ways similar. I think it symbolized that she learned to love in a Christian manner.

From my interpretation I don't think he was her actual son, but her son in the religous sense. It seems that when she is alone with the Misfit she is just sputtering off anything that has to do with religion and salvation, and her reffering to him as her son is just something she said. The part when she reaches out and touches her shoulder and refers to him as her son reminds me of a priest reaching out to touch someone who is sick, as if to give them the power and spirit of god... That's just my take on it.

I think she was speaking metaphorically. I interpreted her comment on him being one of her own babies as meaning that they were both "of good blood," and not "common." Throughout the story that seemed to be what the grandmother was focused on, and it was one of her only defenses in the face of death.

Just my opinion, of course. There are lots of ways to interpret that, I'm sure.