Good for her — but this story illustrates why 90-year-olds should be living with family, not alone.
Our neighbor slipped and fell into the empty tub and landed on her face. Bruises all over. She finally was able to get up on her own and call for help, but now has a thing she wears around her neck that she can activate for help if she needs it.
There are plenty of options for washing besides the usual tub.