Ford has remained out of the public eye since her husband died in 2006.
"She's growing old gracefully, and she's living a life she chooses," her daughter, Susan Ford Bales, told The Detroit News last week. "When you're 91, that's your choice."
Ford was a high profile first lady during her husband's two years and five months as president. She raised awareness about breast cancer when she had a mastectomy in 1974 and made no secret of her support for abortion rights and the Equal Rights Amendment.
After she and her husband moved to California, she went public with her substance abuse problems.
Bales said that even though her mother no longer talks to reporters she remains interested in the news.