Yvonne is the instructor of the aerobics class at the health spa where the women work out at. When she came over, Blanche complained that if you go to a women's only gym, you get hit on by women. Yvonne explained she worked there, and Rose responds with "She just thought you were a lesbian". Yvonne seems to be skilled at persuading new members of her class to buy the expensive gear, such as leg warmers and sports bras. Blanche and Dorothy end up buying everything she recommends, but Rose sticks to her sweats.
When the class begins, she begins with stretches (which Blanche has no trouble doing), then other aerobics moves - until she pulls a Charley Horse, which Rose assumes is another move. Dorothy, however, informs her "She has a cramp, you pea brain!". The girls only went twice to this class, which implies Yvonne's teaching skills weren't quite up to scratch. This experience discouraged the girls from going to a health club to look good for a summer beach party.