From 150 lbs she is down to 105.
She lives in a lovely apartment.
Her kitchen is well stocked, she eats a healthy breakfast at home .
She goes out to eat regularly and often orders a chocolate milkshake after a generous, well balanced meal.
Yet she continues to lose weight.
She is generally active, using a walker to shop and do errands with her companion.
The companion is taking on more housecleaning duties but she still does her own laundry and changes her sheets and straightens up her apartment.
She does have arthritis and a colostomy.
Her heart is strong and though she has fallen a few times she has never broken a bone!
She knows what she likes and what she wants and is demanding, usually getting it.
Best of luck
You cannot expect a 96 yo gut to do the work that a 40 yo gut did. Just one more lovely part of aging. I've become lactose intolerant as I have gotten older and much more sensitive to overeating--I have to really watch the dairy.
My mom has maintained a weight of about 140 lbs for years, eating whatever she wants, but pretty much just 2 meals a day. She is almost immobile, so she isn't burning many calories at all.
My MIL has GAINED a lot of weight in the last few years and told me she was over 180lbs after always weighing about 130 all her adult life. I think she eats a lot and is also pretty immobile, but IDK, I'm not in her life.
I think at 96, you should just let her have what she wants. Short of a physical problem, which should be ruled out by her Dr., just let her be.