Abbie Cornish delivers a strong, internalized performance almost as spare as the title in “The Girl” (2013), a drama about a single mother facing heartbreaking struggles on both sides of the Texas-Mexico border. Cornish (the Aussie lead of “Bright Star” and “W.E.”) plays Ashley, a minimum-wage slave who’s lost custody of her young son, and is also beginning to lose hope of ever getting him back from foster care. When her good-times trucker father (Will Patton, “Falling Skies”) invites her along on one of his regular shipping runs over the border, she realizes that his recent windfall has come from smuggling illegals in his tractor trailer. Desperate, Ashley gets an idea: get in on this “coyote” racket herself. Full story for BostonGlobe.com subscribers.