The Cellar Dweller by Maria Dahvana Headley
Published in Nightmare 33, June 2015
Description, by Sam Tomaino [SFRevu]: "In a town, there are dark things that dwell behind the cellar door. There also dwells the Banisher. She starts out as a nine-year-old, but not a pretty child. She has a thriving business, "advertises her services particularly for the banishment of gremlins, poltergeists, pixies, and nixies. She does a side business in rats, raccoons, starlings, and mice. They come with the territory." She grows up and goes to college, graduating with honors and leaving that business behind. But that is not the end of her story. "