Mary Cooke (Polly) Jones, 68, a former president of the of the Association of Foreign Service Wives and widow of Ambassador G. Lewis Jones, died Monday at Georgetown University Hospital following a heart attack.

Mrs. Jones, who was born in Washington, graduated from the National Cathedral School for Girls in 1930 and from Byrn Mawr College in 1934. The following year, she married Mr. Jones, then a young Foreign Service officer, and accompanied him to Greece, where he was stationed until the German occupation of that country in 1941.

Their next assignment was Cairo. where their first child was born. Later assignments included the State Department in Washington and Britain and Iran. In 1957, they went to Tunisia, where Mr. Jones was the first U.S. ambassador.

In addition to serving two terms as president of the Association of Foreign Service Wives, Mrs. Jones was a member of the National Cathedral Association and for many years was a tour guide at Washington Cathedral. She also was a member of the Sulgrave and Chevy Chase clubs.

Her husband died in 1971.

Survivors include three children, Christopher G. L. Jones of Hamden, Conn., and Virginia L. (Robin) Jones and Andrew Calder L. Jones, both of Washington; one sister, Mrs. Robert F. Woodward, also of Washington, and two grandchildren.

The family suggests expressions of sympathy be in the form of contributions to the Polly C. Jones Memorial Fund, c/o The Washington Cathedral, Washington, D.C.