Mrs. Smithwick was the daughter of David and Jeanne Shihadeh of Bryn Mawr, who operated a family rug business, Shihadeh, in Ardmore. Her brother, Peter L. Shihadeh, now runs the business.
David Shihadeh said his daughter graduated from Harriton High School in Lower Merion in 1964 and from Bucknell University in 1968.
He said she went to New York as a young woman and worked for a succession of companies in the investment field. She earned a master's degree from New York University in business and finance.
His daughter loved gardening, tennis and golf, and "most of all, she was a devoted mother and wife," Shihadeh said.
Mrs. Smithwick also is survived by a son, James, and a daughter, Katharine.
A memorial service will be held at 3 p.m. Oct. 12 at the chapel at the Bryn Mawr Presbyterian Church, 625 Montgomery Ave.
Memorial contributions in Mrs. Smithwick's name may be made to the U.S. Widows and Children Fund, 204 23d St., New York, N.Y. 10010.
L. Stuart Ditzen's e-mail address is sditzen@phillynews.com.