As a child she suffered from scoliosis, which prevented her from a pursuing a career as a ballet Dancer. Before being diagnosed, she studied dance at the Joffrey Ballet School, the New England Ballet School in Connecticut, the Boston Ballet and traveled to France. She wore a back brace throughout her time in the ninth grade. She ultimately had surgery to correct her spine. While she was freshman at Yale University, she founded the Connecticut Scoliosis Association and wrote about her experiences with the disease in the book titled Scoliosis: Ascending the Curve. The book was published before she began classes at Yale in 1999.

Beginning in 2004, Lyons appeared in the television series American Dreams, That's So Raven, The Starter Wife, and Desperate Housewives, and has had recurring roles in 2 Broke Girls, The Affair, and Jane by Design.

In film, her most notable acting role to date was as Amy in the 2008 film Welcome Home Roscoe Jenkins. She also appeared in the films The Trap (2005), Protecting the King (2007), and Dark Reel (2008).

In 2014, Lyons married film Producer Max Osswald. She and Osswald have a son, born in August 2017. Lyons co-starred in two films that Osswald produced, the short film To Sonnets and the television film A Deadly Adoption.