In these type of situations I always like to ask questions going into the psychology of such persons.
Repeatedly in the articles it has said how much her life revolved around her daughter. If this was true, if anything were to happen to her daughter that would mess up all that she had obsessively planned for her....
something could have happened to the girl, possibly harm done to her that made the mom think she was better off ending it.
Or she would think that since she was her mother, she was going to have her dead or alive, and there is nothing the court can do about it.