I would set her up in a room of her own. First, it is less overwhelming than an whole house. Also, you will KNOW where she is!! And you can monitor her eating.

Next, just spend quiet time with her. I find sitting on the floor, sometimes even laying on the floor, is the least threatening to the cat.

Feeding her by hand is a great way to gain her trust.

Simply doing something in her room, without trying to approach her, helps her by allowing her to watch and listen to you.

Don't be afraid of set backs, they will happen. I find that the "recovery"time after each "scary incident" will lessen, over time.

Just LOVE her, she will, in time, love you back.