This is an old book (1999) but it is a classic still available. Readers on both Amazon and GoodReads rate it 4+ (out of 5). It is an English mystery, and I'm recommending it to mystery fans who also happen to be caregivers.
The main character is a 90 yo woman, nearly paralyzed, bedridden, but with a sharp mind. Before her death she wants to solve the mystery of other deaths in the past. She has her scrapbooks of many years of photography and a kind nurse to help her in this task.
This is not a book about caregiving, but I found the viewpoint of an invalid very interesting. Maybe you would, too, if you are a mystery reader looking for something a little different.