Which person did Brian Jones have a relationship with who also had three children with Keith Richards?
Stoned (film):  The film also paints a picture of Jones's use of alcohol and drugs, and his relationships with Anita Pallenberg and Anna Wohlin. Anita Pallenberg:  A style icon and "It Girl" of the 1960s and 1970s, Pallenberg was credited as the muse of the Rolling Stones: she was the romantic partner of Stones multi-instrumentalist Brian Jones, and later, from 1967 to 1980, the partner of Stones guitarist Keith Richards, with whom she had three children.
Anita Pallenberg