your intentions are great, but a lot of this depends on your mom? is she truly amenable to ditching cw and sad? sure, she wants to lose weight and feel better, but it will mean major changes and probably defying what her doctors have told her is "healthy."
IF she can overcome this, i think your initial outline is good, and the thought of doing a low-carb "induction" is excellent. how much fruit are we talking? a handful of berries or 2-3 pears? big difference in the insulin impact. you'd also have to teach her how to deal with the low-carb flu. feeling worse before you feel better is a major discouragement to many.
she won't need as much food as you do, and at her age, calories will matter. can she take walks or swim?
you may also want to discuss inflammation and the role certain foods play there. for somebody living with chronic pain this may the key that opens the primal gate for real for her. by ditching crackers and bread, she kills 2 guilty inflammatory birds : crap grains and crap oils.
As I ate the oysters with their strong taste of the sea and their faint metallic taste that the cold white wine washed away, leaving only the sea taste and the succulent texture, and as I drank their cold liquid from each shell and washed it down with the crisp taste of the wine, I lost the empty feeling and began to be happy and to make plans.
– Ernest Hemingway