Unlike the overwhelming majority of national-level players, Duncan didn't participate in field hockey before high school. She said she first picked up a stick in the summer before she entered Shawnee as a freshman, just three years ago.
But she has made incredible strides in the sport. Duncan has committed to the University of Maryland on a field hockey scholarship, and earlier this summer, she was selected to the USA Field Hockey under-19 team after a tryout at the organization's complex in Lancaster, Pa.
"Just getting invited to the junior national camp, that was more than I could have ever wished for," Duncan said. "Then to be selected, I was just thrilled. It showed me that all the hard work had paid off."
Duncan was a soccer player most of her life. She said she felt a "little burned out" after eighth grade and decided to try another fall sport in high school.
She decided against cross-country because "there's too much running," which is kind of odd because Duncan's best asset is her ability to cover ground - although in short, blazing bursts.
"She's just so fast," Toliver said. "She gets going, and she's pretty much unstoppable."
Toliver said it's "amazing" that Duncan has developed so quickly into an elite player.
"She just keeps going and going," Toliver said. "She's one of those kids where we haven't seen the best that she's got. She's going to keep getting better and better through college and hopefully on to the national level."
Duncan said she knows she has to assume a leadership role this season for a Shawnee team that should contend in both the Olympic Conference American Division and South Jersey Group 4, albeit in the shadow of national powerhouse Eastern.
"I can't believe I'm finally a senior," Duncan said. "It seems like freshman, sophomore, junior year, I was always looking up to the seniors. Now I'm going to be that person."
Duncan said she has some extra motivation since she missed much of her junior season because of a broken bone in her left foot, courtesy of a blast off an opponent's stick.
She spent most of the season on the sideline, serving as an unofficial assistant coach.
"It was frustrating not to play, but it was kind of cool being able to help the girl who was replacing me," Duncan said.
Toliver said Duncan might have benefited from the time on the sideline.
"I think it might have made her a better player," Toliver said. "It gave her an opportunity to watch what was happening on the field."
Fully healthy for her final season, Duncan now is racing to make up for the time she lost as a junior.
And she tends to do well in races.