She is Amy's ex-boss. She quit her job after winning a "lottery ticket" that was was really a gag. She later moved on to marry a rich guy. She was shown to have a rude and mean personality.
In "Amy Needs a Shower", she is invited to the baby shower. Amy invited her just because she wanted her to bring a good gift since she married a rich guy. Charlie tells her this is the reason she was invited and Karen leaves with her gift. Karen returns in Teddy and the Bambino seen at the hospital in the promo. It is revealed in the promo of the Bug Prom episode that Karen is Beau's aunt.