"Tallulah" tells the story of young vagabond, Lu (Ellen Page - Whip It, Inception), who lives in a van and is fiercely independent in her hand-to-mouth existence. When a chance encounter incites her to impulsively "rescue" a baby from a negligent mother, Lu, at a loss for what to do, turns to the only responsible adult she knows: Margo (Allison Janney - Miss Peregrine's Home for Peculiar Children, The Way, Way Back), who mistakenly believes she's the child's grandmother.