[2] Hayes was invited to the 2007 Youth Development Festival, a USA Basketball sponsored event for elite sophomores and juniors in high school, biennially at the U.S. Olympic Training Center.

Hayes was leading scorer of the White USA team, which won five of its games to clinch the gold medal.

UConn became interested in Hayes in 2006, when an assistant coach, Tonya Cardoza, saw her playing AAU ball.

Hayes was not a starter at the beginning of the season, but after teammate Caroline Doty was injured, she stepped into the starting line-up.

[11] Hayes was invited to the tryouts for the USA Women's World University Games Team.

[16] In her rookie season, Hayes played 34 games with 17 starts while averaging 8.6 PPG as a reserve on the Dream's roster.

In 2017, with the team's leading scorer Angel McCoughtry deciding to rest during the season, Hayes took on more scoring responsibility in her absence and continued to improve offensively.

By the end of the season, Hayes put up a career-high scoring average of 16.3 PPG, but the Dream finished with a 12–22 record, missing out on the playoffs.

In 2018, with the return of McCoughtry, the Dream was back in the mix for a playoff spot and eventually emerged as a title contender.

On August 10, 2019, Hayes scored a new-career high 34 points in an 87–82 loss to the Indiana Fever.

[19] With McCoughtry sidelined for the whole season with a knee injury, the Dream finished with a league worst 8–26 record.

On September 27, 2024, it was announced that Hayes would appear and play in the inaugural season of Unrivaled, the women's 3x3 basketball league founded by Napheesa Collier and Breanna Stewart.

Hayes was a part of the United States women's national basketball team which won gold at the 2009 Summer Universiade held at Belgrade, Serbia.