Delightful 91 year old lady needs part-time help. Loved ones are close by so time at work is flexible. Big house so you can live in most or all nights, buy some groceries, cook a few meals, take her to some of her appointments, do some cleaning, and basically help to the extent it works with your schedule, and be a companion. The more you cook, the more you eat for free.
Basically, be another loved one to the extent you are able and take the pressure off those who are close by. Obviously a caring person with a good personality is required.