Rosa Petitjean is the school cafeteria woman. She's usually just called Rosa. She has curly hair, a large body and wears an apron.
She can apparently hold up well under stress, such as in Plagued, when she fought the rat army. She, however, passes out at the mention of zombies, as seen in Attack of the Zombies. She was possessed by X.A.N.A. in Temptation.
She did not appear in Season 5.
Relationships with other people
Rosa is shown to be casual and talkative with students, particularly Odd. She will usually give students second helpings if another student is not going to show up, and they ask. Odd is a frequent recipient of this. However, as shown in Triple Trouble, this rule has its limits. She apparently knows a proportion of the students by name, since she knew William's name in Down to Earth; and Jeremie by name when Odd mentioned he wasn't coming.
She can sympathize with students when there's food restrictions, such as in Tidal Wave, when she was forced to limit portions and health restrictions were placed on what preparations were usable.
She seems to treat adults at the school more or less the same, also as shown in Down to Earth with William's parents. She does have her limits, as shown when Thomas Vincent irritated her in Cold War, and she "Meatball-gravy-dunked" him.