Any mother who knows that her child has been bullied must be very anxious and sad, but at this time I hope you can understand that all this is not her daughters fault, she is the victim.
It also has nothing to do with her daughters weak character, do not know how to resist, she has been bullied, very suffering, so must not complain about her daughter at this time, now is the time when she most need parental support.
I know that you have some difficulties in dealing with the transfer of students, but from a procedural point of view is feasible, you can do it, do not give up because of trouble and difficulties.
Your abandonment is not only a way for her to continue to suffer in a bad environment, but also a last despair - if her parents cant help her, it will be a bigger blow.
So, firmly go to transfer school, work to make money for the future of the child, but now more urgent is to help her out of the predicament.