Thompson successfully petitioned the LPGA to receive a waiver to the rule that LPGA Tour members must be at least 18 years old, allowing her to enter the 2011 LPGA Qualifying School for Tour membership in 2012. The first of three stages was held July 26–29, 2011, at the LPGA International course in Daytona Beach, Florida. Thompson won Stage I by 10 strokes, shooting −23 (66-66-66-67=265). The top 50 finishers and ties from the first stage advanced to Stage II. After winning the Navistar LPGA Classic, Thompson withdrew from qualifying school and petitioned the LPGA for membership based on her win. Her petition was approved on September 30, 2011, and Thompson became a member of the tour for 2012.