Laurie Collyer’s Sherrybaby is the feminine flip-side to Ryan Fleck’s Half Nelson, less because its narrative centers on a Caucasian heroin junkie working with African-American children, and more because it’s a similar bit of trite indie melodrama bolstered by a searing lead performance. As Sherry Swanson, a recently paroled addict determined to win back custody of her young daughter Alexis (Ryan Simpkins), Maggie Gyllenhaal dives headfirst into unglamorous wretchedness, the actress infusing her ugly character with a foundation of authentic pitifulness even during spurious “Look how I’ve hit rock bottom” moments marked by breast-flashing. The rest of the film, alas, exhibits little of its star’s genuineness, forcing its on-the-skids protagonist to tackle a veritable checklist of contrived obstacles – a humiliating job interview, tense confrontations with a tough-love parole officer (Giancarlo Esposito), and a traumatic encounter with her incestuous father (Sam Bottoms) – before arriving at the predestined cathartic climax. As implied by the film’s title and confirmed by her mismanagement of relationships and responsibilities, Sherry is a troubled child in a slutty adult’s body. However, by the time Gyllenhaal’s needy little girl lost, in the film’s phony centerpiece, embarrassingly interrupts a family reunion dinner to belt out the Bangles’ “Eternal Flame,” what’s clear is that, even more than the immature Sherry herself, it’s Sherrybaby’s storytelling that’s truly underdeveloped.