and we all rejoiced.

Then a few weeks later she said she was having 2nd thoughts. At that point the process was already well under way and 2nd interviews were being done for her replacement. I think she knew she wasn't a great employee and was fairly fortunate to be where she was.

That didn't stop her "resignation" however much she may have wanted to. She even commented once or twice that "it feels like you're just forcing me out now" which was basically true. Once she offered that option, there was no way she was coming back.

I would guess your former employee is the same way. She'll always blame others but when she's being honest with herself, she knows she doesn't have too much to offer an employer. I'll bet she'll try to figure out a way to come back too - though you might not ever hear about it. She'll just ask around and see if she can figure out how to do it without swallowing her pride and actually asking since she likely knows the answer.