The Adventures of Piggley Winks (for which she received two nominations for the Daytime Emmy Award for Outstanding Performer in an Animated Program and won once), and portraying Terry Perry in Lab Rats.

Flanagan's live-action film work include appearances in Phone Booth (2002), The Number 23 (2007), Evan Almighty (2007), 500 Days of Summer (2009) and Transformers: Dark of the Moon (2011).

Flanagan has numerous theater credits including working with writer/director Justin Tanner in his plays Oklahomo!, Wife Swappers, Pot Mom, and Zombie Attack!

In 1996, she moved to Los Angeles with the stage production of The Bad Seed, which won an LA Weekly Theater Award for Best Comedy Ensemble.

[10] Also in 2009, she appeared in Marc Webb's romantic comedy drama 500 Days of Summer and Justin Tanner's play Voice Lessons.

[14] From 2012, Flanagan starred as Terry Perry, principal of the Mission Creek High School in the Disney XD live-action comedy series Lab Rats, she was in the show for four seasons until it ended in 2016.