Dorothy McDonald, who co-owned and operated the William J. McDonald advertising and public relations agency in Leesburg, died Nov. 12 at an assisted living center in Marlton, N.J. She had congestive heart failure and died one day before her 91st birthday.

The death was confirmed by her daughter, Margaret McDonald-Laney Willard.

Mrs. McDonald and her husband ran the advertising and public relations business from 1964 until his death in 1991. She was then the sole owner until shuttering the business in 1996. She moved to New Jersey from Leesburg about two years ago.

Dorothy Willis was a Baltimore native and a 1946 speech and drama graduate of the University of Maryland. As a young woman, she was active in theater groups in Warrenton, Va., and the Loudoun County community of Waterford.

In 1953, she co-founded and spent a brief period as head­mistress of the private Loudoun Country Day School. She was headmistress of the private Millvale School in Waterford in the mid-1950s.

Mrs. McDonald ran as an unsuccessful Republican candidate for the Virginia House of Delegates in 1957. She founded and was first president of the Loudoun County Republican Women’s Club.

She was a former president of the Leesburg Garden Club. Her other memberships included St. James’s Episcopal Church in Leesburg.

Her first husband, William H. Krehnbrink, died in combat in 1944 while serving with the Marines on Guam. In 1947, she married William J. McDonald.

Survivors include a daughter from her first marriage, Margaret McDonald-Laney Willard of Marl­ton; two grandsons; and four great-grandchildren.

— Adam Bernstein