If you want to review training techniques, you can look through the aggression section of the forum. I'm not really comfortable trying to explain everything you need to understand to make this work. I still think your best bet is to consult a trainer. In the meantime, manage the dog to keep her and others safe. No playing with dogs.
When a dog saves the life of a man, it becomes clear that partnership knows no bounds.
Fama - T.E.D.D. OEF XI-XII (GSD)(RET... )
Marshall - T.E.D.D. OEF XII-XIII (Lab)(SF EDD)
Lucian - Med Alert (Cane Corso)
Pud - the old man (Pit x Lab)