Wow! What a surprise! I'm glad she was well enough to call -- that bodes well for her recovery even if there is further treatment, though I can fully understand why that is alarming. I'm glad there won't be such a long wait before you reconnect.
(BTW, I'm sure she did not think you were being a burden -- since you did not know what was going on with her and she chose to not let you in, I know she understood your reactions. They were perfectly normal. Any of us would have felt the same.)
It will be a little awkward ahead, but at least you will be with her.