She competed in the Women's 1500 metres event at the 2015 World Championships in Athletics in Beijing, China.

[2] On July 18 in Heusden-Zolder, Belgium at the 2015 KBC Night of Athletics meet, Johnson placed second, clocking 4:04.17 to secure her spot on Team USA.

[3] Johnson won the 2016 Sir Walter Miler in a meet, outdoor North Carolina state and personal record of 4:25.04 (and her first sub-4:30 Mile), and six days later, at the third stop on the BBTM Grand Prix Tour 2016, she won the ServiceNow West Chester Mile, stopping the clock at 4:31.33.

[5][6] Athletes filed a Title IX lawsuit in 2022 alleging sexual abuse by Nicholas and a program of forced doping by the coaches.

[9] At Huntington University, Johnson earned All-American honors in track, cross country, and basketball.