At the 2018 USA Championships in July, Stadden won the bronze medal in the 200 m backstroke.
The following month, she competed at the 2018 Junior Pan Pacific Championships and won the gold medal in the 200 m backstroke with a championship record time of 2:09.52.[2]
In June, Stadden competed at the 2021 U.S. Olympic trials. She finished fifth in the 100 m backstroke and fourth in the 200 m backstroke and did not qualify for the Olympic team.
At the 2023 NCAA Division I Championships in March, Stadden won the bronze medal in the 200 y backstroke and finished sixth in the 100 y backstroke.
In July, Stadden competed at the 2023 USA Championships. She finished fifth in the 50 m backstroke, fifth in the 100 m backstroke, and sixth in the 200 m backstroke.