The troubled heiress who never fit in is a familiar trope, but when that heiress is the trailblazer Peggy Guggenheim, the narrative expands to encompass the history of modern art. Famous for opening the Venice branch of her family’s museum, which holds her stellar collection, Guggenheim, who died in 1979 at the age of 81, is the subject of a documentary by Lisa Immordino-Vreeland. The most rewarding moments of “Peggy Guggenheim: Art Addict,” premiering November 6, come when we learn how the insecure, often unhappy collector championed the greatest artists of the day at the galleries she ran in London and New York. Married for a time to the painter Max Ernst, Guggenheim gave a crucial early boost to Jackson Pollock, Vasily Kandinksy, Robert Motherwell, and many others. Immordino-Vreeland gets help in telling her tale from a 1970s audio interview with Guggenheim, in which the patroness reminisces about everything from sleeping with Pollock to putting on one of the first-ever shows devoted exclusively to women artists. Guggenheim compares her role in the art world to that of a “midwife,” perhaps too humbly, as the film surely proves that, in her care, a great art legacy was born.