She took a job as a crew member for the Blue Man Group, then won a role as Maid Marion in a touring production of Robin Hood.
Despite the grueling experience of the Robin Hood tour, Allen decided she wanted to focus on acting.
[4] Allen began working as a waitress while interning at the MCC Theater, where she met Robert LuPone.
[2] She auditioned unsuccessfully for the roles of Michelle Bauer on Guiding Light and Melanie MacIver on One Life to Live before being cast as Laura Kirk-English on All My Children.
[2] After departing AMC, Allen went on to play Susan Delacorte in Mike Newell's Mona Lisa Smile.
[2][6] In 2004, Allen was cast as Samantha Wade in Sucker Free City, a Showtime film directed by Spike Lee.
[9][10] In 2007, Allen was cast in a regular role on the FX drama series Dirt, playing Julia Mallory.
[10][11][2][12] Allen played a recurring role on Grey's Anatomy in 2009 as the ex-lover of Owen (Kevin McKidd).
[26] In the 2018 film The Tale, a drama about sexual abuse, Allen played a younger version of Ellen Burstyn's character.