Ruck was part of the gold medal 4 × 200 m freestyle 2017 World Junior Swimming Championships team in Indianapolis. In the process the team broke the junior world record and championship record. Ruck would add gold medals and world junior records in both the 4×100 m relay and the 4×100 m medley. She set the world junior record in the girl's 100 m backstroke semis, but would lose the record and the gold medal to Regan Smith while winning the silver medal in the event. While swimming in the 200 m freestyle event, she lowered the championship record twice when she set a 1:57.08. Ruck also set a 100 m championship record while leading off the 4×100 m relay when she swam to a 53.63.