Karen's Chicken Pox is the 114th book in the Baby-Sitters Little Sister series.
Back Cover SummaryEdit
Halloween is coming! There will be a party at school. And Karen, Hannie, and Nancy have planned the best costumes ever. Then Karen's little sister gets the chicken pox. It is very contagious. Karen does not want to catch chicken pox. If she does, it will ruin Halloween. And that would be really scary!