Along with her twin sister Holly, Lucy attended Stony Brook University in New York until 2012, earning an undergraduate degree in sociology followed by a Master of Arts in Liberal Studies (MA/LS).
She was chosen an NCAA All-American for outdoor track (2010, 2011 and 2012), indoor track (2011 and 2012) and cross-country (2011).
She competed in the 3000 m at the 2014 World Indoor Championships.
At the 2014 Commonwealth Games, she competed in the 1500 m and the 5000 m.At the 2016 Olympics, she competed in the 5000 m.