My mom shrank like crazy in the years before she passed away. In photos where she stood next to me in the year before her death, she looked almost half the size of me. I think women especially look smaller because they tend to get that humpback thing more than men do.
I think most people who live to that age or longer are generally pretty small and thin. You don't see a lot of big fat people in their 90's, because their bodies gave up in their 60s-70s.