Macario was born in São Luís, Maranhão, Brazil. At a young age, her family moved to Brasília. In 2011, at the age of 12 and without speaking any English, Macario relocated with her father and brother to San Diego, California, in order to pursue her dream of playing soccer. Her mother, a doctor, remained in Brazil in order to financially support the family.
On February 1, 2017, Macario committed to play collegiately for Stanford University. In her freshman year in 2017, she played 25 matches, scoring 17 goals and clinching 16 assists. As a result of her performance this year she won several awards, including being named "ESPNW Player of the Year", "TopDrawerSoccer.com Freshman of the Year", "Pac-12 Forward of the Year", and "Pac-12 Freshman of the Year". In her sophomore year in 2018, Macario scored 14 goals with 8 assists in 19 matches played. On December 11, 2018, she received the TopDrawerSoccer.com National Player of the Year Award. On January 4, 2019, Macario won the MAC Hermann Trophy, awarded to the nation's top female and male players. Additionally, she was named "espnW Player of the Year" and "Pac-12 Forward of the Year" for the second year in a row. In her junior year, Macario was the winner of the Honda Sports Award, given to the nation's top female collegiate soccer player. She was also awarded the MAC Hermann Trophy a second time, becoming the sixth woman to repeat as winner since the award was established in 1988.
International career
Macario is eligible to play internationally for Brazil and has yet to receive American citizenship. Despite that fact, she was called to represent the United States at several youth levels. Macario stated that she intends to represent the United States at the senior level, turning down several approaches from the Brazilian Football Confederation. She will become eligible to play for the US women's national team at age 23 if she lives in the country for five years continuously up to that date; she could also become eligible before then if she can convince FIFA that she came to the US to better her life beyond playing soccer.
Personal life
Despite declaring herself Marta's fan, Macario stated that her favorite soccer player is the American former forwardMia Hamm.
Honors
ESPNW Player of the Year: 2017, 2018
Hermann Trophy: 2018, 2019
CoSIDA Academic All-District 8 first team: 2018
TopDrawerSoccer.com Freshman of the Year: 2017
TopDrawerSoccer.com Player of the Year: 2018, 2019