Her daughter feels very lousy about herself. (as you know already!) She also feels like she has no control over her life or over anyone. She is desperate to hang on to this boyfriend with a feeling of absolute terror that he may go, as she feels she may lose control of herself. She also feels that no one listens to her and she has no power over anything that happens.
In a way, she wants her own way so badly, she is prepared to hurt herself. There is a lack of immaturity here and the supposed notion that we can control the actions of others by making them do what we want them to.
I know this because I had a period of time where I felt the same.
What she needs is love, affection, and to be talked to and listened to. I had a couple of years of group therapy and learned to express myself, my wants, needs and desires through the medium of words rather than 'attention seeking' methods, which are only really understood by the person doing them.