Shevell, 51, wore a flower in her hair and a long-sleeved, knee-length ivory dress designed by her new stepdaughter, Stella. McCartney's daughter also made her father's navy suit.
Wedding guests included Shevell's son Arlen, her second cousin Barbara Walters, McCartney's brother Mike, The Beatles' Ringo Starr and his wife Barbara Bach, and George Harrison's widow, Olivia. "The wedding was lovely," Walters said afterward.
During the intimate ceremony, McCartney -- who has been married twice before -- presented Shevell with a Neil Lane eternity band featuring 5-carats of square-cut diamonds set in platinum.
Following their nuptials, the newlyweds were feted at McCartney's home in St. John's Wood, where guests including The Rolling Stones' Ronnie Wood, Charlene Spiteri, Jools Holland and Kate Moss feasted on a decadent menu that included savory tarts, vegetable gyozas and two weddings cakes -- one vegan (made with apples) and one chocolate.