Hi, sorry to be late on this but I am so impressed with your journey for your mom. In no particular order:

How's her mineral supplementation? The comment about no taste got to me - if a person is low on zinc and magnesium that can happen. It did to me. Very common after years of a diet heavy in sweets and starches (which depletes minerals).

In the Lutz book, he says that the oldest people see improvements in health by restricting to 72 grams a day or even 90. This is from the thinking that you don't have to be in constant ketosis to get a better metabolism. Overnight is fine like in the old days. The transition might be easier for her.

Custards made with cream or half and half can be rewarding to older people. Or plain old custard pie with an almond flour crust and vastly reduced sweetener.