Johnson was born in Cameroon to an American father and Malian mother. She moved to multiple countries for her father's job but her family eventually settled in Colorado when she was in elementary school. She grew up in Fort Collins where she was a four-year letterwinner at Rocky Mountain High School. As a freshman, Johnson was named the best defensive player by the team. She earned all-conference first team honors as a freshman, sophomore and junior and was named all-state during her junior and senior years. She was named team MVP as a sophomore and a junior. Johnson was a member of the Olympic Development ProgramRegion IV pool. She also captained the club team, Fort Collins Arsenal.
Johnson attended the University of Kansas where she played for the Jayhawks from 2006–2009. During her freshman season, she appeared in all 19 matches with 18 starts. She ranked fifth on the team with 1445 minutes played and helped the Jayhawks shut out eight opponents and hold 0.98 goals against average. She was named to the Big 12 All-Newcomer Team and was selected to the Cal Invitational All-Tournament Team. As a sophomore, she started all 21 matches for a total of 1,883 minutes – third most on the team. She was named Third Team All-Central Region by Soccer Buzz. During her junior season, Johnson started all 23 matches, playing a program-record 2,110 minutes. She was named All-Central Region by Soccer Buzz and the National Soccer Coaches Association of America as well as to the Big 12 Championship All-Tournament Team and academic all-conference team.
Club career
Philadelphia Independence
Johnson was selected by the Los Angeles Sol during the 2010 WPS Draft; however, the team folded before the 2011 season and Johnson signed with the Philadelphia Independence as part of the 2010 WPS Dispersal Draft. She made 16 appearances for the club, including 13 starts. Johnson joined the Independence for the 2011 season. She made 15 starts in 17 appearances for a total of 1,403 minutes and scored one goal.
Johnson was traded to the Spirit on February 24, 2015 in exchange for defender Toni Pressley. In her first season with the Spirit, she played in all but one game, logging 1685 minutes. In 2016, Johnson played in eleven matches, totaling 990 minutes. She has started in 30 of her combined 31 appearances over the two seasons.
Johnson became interested in playing for Cameroon, her country of birth, after watching the team reach the Round of 16 in the 2015 FIFA World Cup. She struggled to work out the details with the team, until coach Alain Djeumfa joined the team in January 2019 and her place on the team was finalized. Johnson was named to the Indomitable Lionesses' squad on 1 May 2019 and made her debut 16 days later against Spain in a 0–4 friendly loss. The same month, she was named to the final roster for Cameroon for the 2019 FIFA World Cup in France. At the 2019 World Cup, Johnson played every minute in the Lionesses' four matches, spanning three group stage games as well as the team's 0–3 loss to Englandin the Round of 16.
