One of two siblings, she was born in San Diego to Abraham and Anne Ratner on Jan. 26, 1934. She grew up in Kensington and graduated from Hoover High, and then attended Reed College in Portland, Ore. Relatives there arranged a blind date with Stanley Foster, who ran a furniture store.
The couple came to San Diego and got married in 1953. He started working for her father’s clothing business and became president in 1970. While he was buying the Hang Ten sportswear line for $3 million and turning it into a $200 million retail juggernaut, she was raising their three daughters and running the family home in Point Loma.
By the 1980s, Mr. Foster had sold Hang Ten and diversified the company into real estate and other investments. He and his wife shifted more of their attention to community affairs and philanthropy.
Among her board appointments: the UC San Diego Foundation, the La Jolla Playhouse, the Sanford Burnham Prebys Medical Discovery Institute, and the National Council of Jewish Federations and Welfare Funds.
After her husband died in 2001, Mrs. Foster made major donations to UC San Diego in his memory. A $5 million gift created an endowed chair at the Rady School of Management. Another $7.5 million went for a new cancer-care hospital at the Jacobs Medical Center.
At the Museum of Contemporary Art, her involvement dated 30 years, to when she joined the board of trustees. She and her husband were founding members of the collectors club and funded new galleries at the La Jolla and downtown sites. She also donated a 25,000-square-foot storage facility to house the museum’s collection.
Survivors include her daughters, Marcia Hazin (Mark Cammell) of Poway, Lisa Foster (Alan Bersin) of Washington, D.C., and Karen Silberman (Jeff) of Rancho Santa Fe; nine grandchildren; and three great grandchildren.