Last night and this morning Brea made up for the frustration I felt on Saturday. Her favorite place is on the rug next to my bed. Although she still doesn't come downstairs when I call her, she did come downstairs with me without trying to hide or escape three times in a row when I went upstairs to her and said, "Go outside, go potty?" Each time, she got up and headed down the stairs and sat at the front door while I put her leash on her. It feels good when that happens, like she's becoming familiar and comfortable with the routine, and more comfortable with me.
I found a website which looks helpful: http://fearfuldogs.com/, created by Debbie Jacobs, and I ordered a copy of her book, "A Guide to Living With & Training A Fearful Dog."
So today feels like one of those days when we've made a tiny little bit of progress.