A veteran coach with extensive big wins over Moorestown, Good Counsel, Vero Beach and Bishop Ireton she built Agnes Irwin into a Top 20 power in her five years there, posting a 98-23 record despite taking over a team that was 2-16 the year before she arrived. She was named Phillylacrosse.com Coach of the Year in 2015 when she guided the Owls to a 23-1 record, the Inter-Ac crown, the PAISAA crown and a No. 3 ranking in the final STEPS Lacrosse North America Rankings.
Coach Duck has guided many local players to be recruited and find their fit academically and athletically at top national collegiate D1-2-3 programs.
Duckenfield mentored 13 U.S. Lacrosse All-Americans, 15 Academic All-Americans and three representatives to the Under Armour All-American game.
Agnes Irwin has produced 13 girls lacrosse All-Delco picks, including 2015 Player of the Year Hannah Keating. As demonstrated by Keating, the 2014 Girls Soccer Player of the Year, Duckenfields development of the lacrosse program had a knock-on effect at a school known for multi-sport athletes. The last five years, Agnes Irwin has earned 37 All-Delcos lacrosse honors, compared to just 14 total in the decades before. Voted coach of the year 2015, runner up 2014.

Coach Duck has mentored many of her players to the coaching helm. One daughter Alex Daughter All American graduate Strath Haven and was named All Big East and ACC league honors playing at Vanderbilt University.