Nymeyer is a Tucson native who graduated in 2004 from Mountain View High School (Marana). She is also a graduate of the University of Arizona where she majored in physical education. Away from her own training, Nymeyer leads swim clinics and speaks to youth groups. She is also a substitute teacher and plans to teach full-time when her swimming career ends. Nymeyer's mother, Stacey Nymeyer, blogged about her daughter's experiences in Beijing for Arizona's KVOA, News 4.
Nymeyer competed for the University of Arizona in Tucson, her hometown. During Nymeyer's senior year, the Wildcats won the 2008 NCAA Women's Swimming and Diving Championship. Nymeyer was a member of the 200 yard free relay, 400 yard free relay, 400 yard medley relay, and 800 yard free relay, which all won first place. Additionally, Nymeyer is an individual NCAA champion in the 200y freestyle (2007) and 100y freestyle (2008).
Nymeyer was named the "2009 Woman of the Year" for the Pac-10 Conference and represented the conference in the national competition. On October 18, 2009, Nymeyer was named the "2009 NCAA Woman of the Year" which honors female student-athletes who have completed their eligibility, demonstrated academic and athletics excellence, and engaged in community service and leadership opportunities.
At the 2008 Olympic Games in Beijing, Nymeyer was part of the 4x100 m freestyle team that won the silver medal. Nymeyer also competed in an individual event, the 100 m freestyle, and placed 12th overall.