This World Alone.

Following a cataclysmic event which left the Earth without technology or power, Sam (Belle Adams)—a book-obsessed girl in her late teens—lives in seclusion with her two mother-figures (Carrie Walrond Hood & Sophie Edwards). But after an accident, she’s pushed out of her protective world and forced to put her makeshift parents’ opposing world-views to the test as she faces the physical and emotional challenges of a world reclaimed by nature. (Synopsis taken from the film's official site.)