Maguire broke through for her first LPGA Tour victory at the 2022 LPGA Drive On Championship in Florida, and added a second at the 2023 Meijer LPGA Classic for Simply Give in June. She became the first player from the Republic of Ireland to win on the circuit. This came after a highly decorated amateur career that saw her represent Great Britain and Ireland three times in the Curtis Cup, and win the McCormack Medal three consecutive years (2015-17) for being the No. 1 player in the World Amateur Golf Ranking. She surpassed Lydia Ko's mark of consecutive weeks at being ranked No. 1 in the WAGR at 131. She set the mark at 135 weeks atop the WAGR. At Duke University, she twice was named the winner of the Annika Award for being the nation's top female collegiate golfer (2015 and 2017). In 2017, she won the Women's British Amateur conducted by The R&A. She represented Ireland in the Women's World Amateur Team Championship in 2010, 2012 and 2016. Has a twin sister, Lisa, who also played at Duke. The two were on the 2010 GB&I Curtis Cup Team as 15-year-olds. Before turning professional, she represented Ireland in the 2016 Olympics in Brazil. She also played again in 2021 in Tokyo.