In September, Lee competed at the US World Championships trials, where she placed second in the all-around behind Simone Biles, losing by only 0.350 points. The following day she was named to the team to compete at the 2019 World Championships in Stuttgart alongside Biles, Kara Eaker, MyKayla Skinner, Jade Carey, and Grace McCallum. She was the only first-year senior named to the team and the only team member without prior World Championships experience.