Regardless of where she is now, she has had to endure 2 years of looking over her shoulder and second guessing herself. That type of conditioning doesn't go away in a month. If you and your Master truely want to help her, you need to seek out some family counseling/therapy so they can give you ideas and techniques in how to deal with her insecurity and self esteem issues until she gets better. Patience and therapy are probably the only things that are going to help her.
This is very true, I have had to deal with this issue before, and it can be frusterating, but time, patience, and therapy is key to this. it is not something that will be over and done with in months, but may in fact take years to over come compleatly. Possitive renforcement is also key, let her know when she does something good or right, and how proud you are of her, even when it is a little thing, let her know how happy you are to have her as a part of the household. This will give her a reason to keep trying. this is something both of you need to do. With someone who has been through that much abuse, she is going to jump at the slightest things, many of my friends thought for months that I was abuseing my little one, because of these little jumps, untill it was understood what she had gone through. These are friends who have known me for years, as one who is very protective of those in my house, and not one to be abuseive, but very antiabuse.