So sorry to hear that. Best wishes to your mom.
I am a lawyer in Calgary but I do not work in this area. If I were to refer a client for this sort of thing I would typically recommend one of:
Jared Kantor -
https://www.kantorllp.ca/estate-liti.../jared-kantor/
Darryl Aarbo -
https://aflawyers.ca/lawyers/darryl-aarbo/