Besides her work as a photographer, Ms. McCartney performed as a keyboardist and backup singer in two of her husband's post-Beatles bands, Wings and the unnamed ensemble that toured in 1989 and 1993. She was a staunch campaigner for animal rights and vegetarianism and, starting in the late 1980's, she turned her passion for vegetarian cooking into an industry. the McCartneys' 29-year marriage was uncommonly steady by the standards of the celebrity world of which they were a part but from which they generally remained aloof, spending most of their time on a farm in West Sussex, England. They never spent a night apart, except for the 10 days Mr. McCartney spent in a Tokyo jail after he was arrested for marijuana possession; indeed, their disinclination to be separated was part of Mr. McCartney's reason for having his wife in his touring band. Her father, Lee Eastman, was a prominent show business lawyer in New York.She was born Linda Louise Eastman on September 24, 1941, and grew up in Scarsdale, N.Y. As she often pointed out, without ever dispelling the assertion entirely, she was not related to the Eastmans of the Eastman-Kodak photography empire. In fact, her father had changed his name from Epstein. Ms. McCartney attended Sarah Lawrence College and the University of Arizona. While a student in Arizona, she married and had a daughter, but the marriage ended in 1963. Soon afterward, she took up photography, and in 1965 she returned to New York, where she began photographing rock groups, starting with the Dave Clark Five and the Rolling Stones. Ms. McCartney met her future husband while photographing the Beatles in London in 1967, and the pair carried on an occasional romance for more than a year. In September 1968, Mr. McCartney asked her to move to London, from which point they became inseparable. In addition to Mr. McCartney and the daughter from her first marriage, Heather, Ms. McCartney is survived by three children from her marriage with Mr. McCartney: Mary, Stella and James; and by her brother John, who is now Mr. McCartney's lawyer and business manager, and two sisters, Laura and Louise.