Wendy is a girl in Caillou's playschool class. She started coming to the playschool in the episode Caillou the firefighter. She makes cameo apperances in episodes that take place at the playschool.
- Caillou the firefighter (cameo)
- Caillou goes toboggaining (cameo)
- Deep sea Caillou (cameo)
- Caillou the astronaut (cameo)
- Caillou the creative (cameo)
- Caillou the police officer (cameo)
- Caillou's puppet show (cameo)