In early January, Sonnett was called up for the annual USWNT camp that was held in Orlando.[146] At the conclusion of camp, Sonnett appeared in both international friendlies as a full back against Colombia and registered an assist to Megan Rapinoe's goal during the January 22 match-up.[147][148] In February, she was named as one of the 23 players to represent the United States during the 2021 SheBelieves Cup.[149] Sonnett appeared in all three matches during the tournament, starting and putting in the full 90 minutes against Brazil as right back.[150][151] During the final match of the tournament against Argentina, Sonnett was subbed in at the 32 minute mark for O'Hara and played in the right back, left back, and center back positions.[152] The USWNT went undefeated during the tournament and secured their fourth SheBelieves Cup championship title with a 6–0 win over Argentina.[152]