Born in Oakland, California and raised first in Alameda and then Moraga, California. She competed in the International Modeling & Talent Association (IMTA), where she was recognized as the second runner up for "Young Miss Dancer of the Year." She was discovered there by a manager and immediately moved to Los Angeles for her first pilot season at age 13. Her breakthrough role was playing Colleen Carlton on The Young and the Restless for 3 years. Since leaving Y&R, Lyndsy has worked steadily on prime time television, notably as the daughter on the TV Series How I Met Your Mother and Dylan Mayfair on Desperate Housewives, and in several movies including Kick-Ass and Hot Tub Time Machine.

Lyndsy is also an accomplished dancer and unwinds in dance classes when she is not working. She has a younger sister, Hannah Leigh Dworkin, who is following in her footsteps.