I understand your anger and I agree that a depression is not a valid reason to steal from people. But I do feel sad for people being in such a situation.

The 'positive' part is that she does seem to feel sorry for what she did. She could also have ignored your post, create a new account and start scamming again (which still is possible by the way).
Also the fact that she mentioned that she wants to return the money is a positive sign. Whether she will actually do it will remain unsure.

I think it is a good decision that you let it go now.