How do we convince Mom she can't live alone?

How long has she been staying with you? What is the set-up at her home - does she have any support structure there?

Thanks I have already started doing that.

Kirb, one thing is not enable Mom-in-law, like don't do as many things around the house to help her. If she wants to go back to her previous residence, she has to prove to you that she is able to do so.