Hitting over 300 kills each season in high school, McMahon was named a two-time first-team All-Greater Miami Conference performer.

[5] As a senior, McMahon started every match as an outside hitter and ended the season with a total of 396 kills and 110 blocks.

McMahon was also named to the Academic All-Big Ten team her sophomore through senior years.

[5] McMahon made her professional debut on the U.S. Women's National Volleyball Team at the 2017 Pan American Cup and became a gold medalist.

The team finished the regular season ranked number 1 in the league, though in the post-season they lost in the Finals, ending as runners-up.

[7] While playing with Hwaseong IBK Altos, she received the Korean V-League's awards for Best Opposite player, Best Spiker, and overall league MVP for the 2015–2016 season.

[10] McMahon has been coaching with Troy Tanner's Tstreet Volleyball Club of Irvine, California, since 2019.