Killingsworth was forced to give up her active lifestyle after several surgeries. She became seriously depressed and credits her work with colored pencils as the activity that saved her. Killingsworth chooses colored pencils because they allow her to render the fine details she loves. She is intrigued by out-of-the-ordinary objects and the artistic possibilities they offer. Killingsworth has designed notecards for companies in New York, Chicago and San Francisco, and has illustrated two books. She is one of the founders of the Yellow Springs Art Show, located in Yellow Springs, Pennsylvania.