When Linda, a magazine photographer, visited England on an assignment, she brought along daughter Heather, who soon had babysitters like guitarist Eric Clapton. When Linda began a relationship with McCartney, Heather's presence was a plus, as McCartney loved children and was eager to start a family.
Six-year-old Heather makes a brief appearance in the movie Let it Be, visiting McCartney in the studio while the Beatles were at work. She dances around as they play, jumps out at Ringo Starr from behind a cymbal (Starr, a father himself, pretended to be scared), and sits on McCartney's lap, while he checks a microphone.
Heather gained a half-sister the next year, as mother Linda became pregnant with McCartney's baby, and the two were married. McCartney adopted Heather, who took his name, and Mary McCartney (named for Paul's own mother) was born early in 1970. Another sister, Stella, became the fashion designer Stella McCartney. A brother, James Louis McCartney, became a musician.