Phillips was the creator of the "Dear Abby" advice column, which her daughter, Jeanne, took over writing in 2002.
"I have lost my mother, my mentor and my best friend," Jeanne told TMZ after confirming her mother's death Wednesday. "My mother leaves very big high heels to fill with a legacy of compassion, commitment and positive social change. I will honor her memory every day by continuing this legacy."
Pauline's twin sister, Eppie Lederer, was also an advice columnist, writing under the name Ann Landers. She died in 2002 at the age of 83.