Copper led the Chicago Sky during the 2021 playoffs, being named WNBA Finals MVP as the team won their first title in franchise history.

[10][11] She was elevated to a starting role in the 2020 season, which was played in a "bubble" due to the COVID-19 pandemic, and led the team in scoring with 14.8 points per game.

On February 6, 2024, Copper was traded to the Phoenix Mercury alongside the rights to Morgan Bertsch in exchange for Michaela Onyenwere, Brianna Turner, the 2024 No.

[18] On July 17, 2024, it was announced that Copper would appear and play in the inaugural season of Unrivaled, a new women's 3x3 basketball league founded by Napheesa Collier and Breanna Stewart.

In September 2022, Copper was named to the USA international team ahead of the 2022 FIBA Women's Basketball World Cup.

[23] Between the 2020 and 2021 WNBA seasons, Copper worked as an assistant coach for Purdue University Northwest's women's basketball team.