Farr was a co-host for 200 episodes of the advice program "Loveline" on MTV and made guest appearances on "The Drew Carey Show", "Arli$$", and "". She portrayed the recurring role of Amy DeLuca, mother to the series co-star Majandra Delfino's character Maria, on The WB's and later UPN's "Roswell". She also played Maddie Hudson on The WB's "Like Family". Later, she played Detective Jan Fendrich on the ABC series "The Job", co-created by and starring Denis Leary. Following the end of that series, she appeared in the cast of "Rescue Me" (also co-created by and starring Leary), playing a firefighter for two seasons. She left "Rescue Me" to star as FBI agent Megan Reeves on the CBS crime drama "Numb3rs".