[1] A dual citizen of the United States and Australia, she is a member of Australian women's national basketball team (the Opals).

[15] Initially a bench player, Mitchell made her first professional start on June 6, 2008, in place of the injured Loree Moore.

In her first career start against the Houston Comets she had team-high 18 points going perfect 6–6 from the floor including 3–3 from three-point range.

During the 2008 season she developed a strong fan following and a reputation for fearlessness in grabbing loose balls and occasionally driving to the basket.

Mitchell scored 14 points in the Liberty's narrow loss to the Detroit Shock in Game 3 of the 2008 Eastern Conference Finals.

[19] On June 12, versus the Indiana Fever, Mitchell scored then career-high 25 points, going 8–14 from the floor including 7–10 from three-point range.

On July 5, Mitchell hit the go ahead three-point shot in overtime with 3.9 seconds, in a 94–91 win over the Los Angeles Sparks.

On August 27, she scored 16 points and made a three-pointer from the top of the key at the horn to give Phoenix an 81–80 win over the Connecticut Sun.

In 2016, Mitchell signed with the Washington Mystics in the second half of the season to fill a roster gap at the point guard position.

Mitchell ended the 2019 season averaging double figure points for the first time in her career as the Mercury finished 15–19 with the 8th seed in the league.

She scored playoff career-high 25 points in the Mystics' loss to her former team Phoenix Mercury in the first round, losing the single elimination game 85–84.

Source[22] During the WNBA off-season, Mitchell has played for ASPTT Arras in the Ligue Féminine de Basketball (LFB), a French professional league.

[25][26] Mitchell planned to start a coaching career with Australian NBL1 team Maitland Mustangs after finishing the 2021-22 WNBL season with the Bendigo Spirit[27] but that playing role came to an end after four games due to pregnancy.

[28] Mitchell has been a regular member of the Australian national team, the 'Opals', since 2014, when won a bronze medal in the 2014 World Championship.

[29] On July 24, 2018, Mitchell's fiancée WNBL basketball player Mikaela Dombkins gave birth to son Kash Maxwell.