Sister Sloey was a young female mouse of Redwall Abbey. As a Dibbun she was friends with Gubbio. During a game of hide and seek, Sloey fell down a former tower of Kotir that was causing one of the Abbey walls to sink. Skipper dove in after her and rescued her, saving her from a giant yellow eel.
As an adult, Sister Sloey became the keeper of Redwall's Infirmary.