In the episode "Boy Bands Will Be Boy Bands" she's shown as a strict yoga instructor for an advanced Power Yoga Chi-(Tae)kwondo class that Sam, Clover and Alex had signed up for, but did not do well in. Clover made a comment after the class saying they should have signed up for the beginner's class and that Shirley had issues. Three of the movements she taught were Long Tiger, Skipping Goat, and Squatting Bear, which the girls used to defeat the evil boy band, Boy Candy, who had kidnapped and stolen the faces of the more popular boy band, Teensicle.
In "Power Yoga Much?" Shirley was driven to bankruptcy by the Kung fu Fondue studio and wanted revenge. She brainwashed her former students to help her destroy the studio. Her combat techniques in that episode were vicious and cunning, but the spies managed to defeat Shirley and return the brainwashed teens back to normal.
- Shirley was one of the few villains to appear well before becoming a villain. Others include LAMOS member Myrna Beesbottom, and one at least one occasion Mandy and Arnold Jackson.
- It is unknown how her hair got clean after she was submerged in the fondue pot in "Power Yoga Much?"
- A Shirley look-alike was seen in "Alex Gets Schooled".