Knowings joined the cast of All That after she had been a performer on a Rosie O'Donnell sketch-comedy special produced by Nickelodeon entitled, And Now This.
Her characters included Penny Lane (inheriting the role from Alisa Reyes, who herself had inherited the role from Angelique Bates), the dental assistant for Dr. Bynes, Lieutenant Fondue, Jessica from Whateverrr!!
!, Yoko from CJ and the Cloudy Knights, Brenda Stone from Channel 6 1/2 News, and Winter Wonders from What Do You Do?
Knowings made a small cameo in the green room for the show's 10th Anniversary Special.
From 2008 to 2011, she made three appearances on episodes of Sesame Street, alongside her real-life twin brother Chris Knowings.