The story said she always worked as a waitress (i.e. no retirement plan there besides Social Security), her husband had Alzheimer's (that probably ate up his retirement savings) and she built a house in the late 1990s, so she's probably still making payments on it.
Regardless, an 81-year-old doing 12-hour night shifts?
You go, Grandma!
There was a woman at my last job who wasn't much younger than this who worked per diem in the peds unit. She wore the fitted white dress, white hose, and a cap.