Gully not wanting to get out of her crate makes sense to me now. It was a place she was actually SAFE! Be patient with her! It sounds like her former owners (abusers) have left emotional issues that go to her very core. You have no idea what abuse was inflicted on her and since she is a rescue this is just one of the things that need to be understood by you!

I personally would not try to MAKE her do stairs. When her trust in you out weighs the pain of her past she will try to do steps on her own if it is a necessity in her life. You just need to be loving and understanding that this is a pain she can not bear! My heart breaks for her!

In the mean time work towards building her trust and love and give her every reason to know you would never do anything to harm her.

She is lucky you are in her life now! Give her a hug and kiss for me, please!