it seems to me for a bird who has known you for such a short time, she is doing really well. I have had two birds that have previously been from other homes, and it takes a wile for her to trust you. She may want out, but is scared to trust you to help her out, same with going back in. I'd advise strongly against 'punishing' her for being 'bad' by trying to bite like you stated that you did, by confining her to her cage. She will take even longer to trust you if her new routine varies so much and if her new person isn't consistent in wanting to spend time with her. Most new birds try to bite or threaten to bite out of fear at first, its all part of building trust. but don't give up, and give her time and praise for the bravery she has shown. best of luck!