Big Sonia, the latest documentary by Leah Warshawski, follows in the socially aware steps of Finding Hillywood, her award-winning 2013 history of the Rwandan film industry. But the Seattle-based filmmaker’s follow-up takes a personal turn: Warshawski’s subject in this absorbing, moving feature is her paternal grandmother, Sonia, a pint-sized, energetic 90-year-old businesswoman whose beloved tailoring shop faces eviction from its location in a Kansas City mall.