First you need to work out if it’s biting out of fear, aggression, or mentally disturbed (inbred) If its fear spend time handling, and playing as much as you can, use gloves until you can touch her without biting. be gentle (don’t listen to people who will tell you, not to use gloves at the start on a grown vicious ferret, NO reason not to they talk shit) If it’s out of Aggression you need to dominate her until she understands you are the boss (many methods of doing this) I normally let them bite the side of my finger hold them by the neck and push my finger hard toward the back of their mouth