Hi,
Sounds as though she is really testing you to see if you will stick around.
If she has been abandoned by a male figure in her life before she probably has huge trust issues.
Children often lose self esteem when there is a broken relationship as they often think it is their fault that things went wrong--They often feel that they must be a really horrible person otherwise that person would not leave her.
It seems as though some really good family therapy would be good but I applaud you for being committed to helping her through this.
Tons of luck
Tayla