In the short story "Mama says" the title sets the tone for the entire short story. Immediatley after reading the title, you can already tell what the short story is going to be about. In this short story, the mom was talking about herself. Most likely, to her daughter.
"I'll teach you how to posion a man before I let that happen to you." After reading this sentence its almost as you can sense the anger of the women behind it. She was hit by a man, clearly. She is trying to teach her daughter to never let a man hit you, or degrade her in any way shape or form.
"One day the doctor tells her she is going to have a baby-" That baby is the little girl that she is talking to and teaching her was that baby. The mother is trying to teach her and show her to never let what happened to the mother happen to the daughter!