[Name] Mary-Lou [Nickname] Mary-Lou [Appeared in Form] Forms 1–6 [Note] 
Mary-Lou is a timid and quiet girl. After Darrell saves her when Gwen holds her under the water in the pool for way too long in the first book, she becomes her companion and rather likes her and Sally. When Darrell is accused of smashing her pen, that night she thinks "Something's not quite right, Gwen changed into slippers instead of her shoes, so I'd better have a look." and lo and behold, Gwen's shoes have ink all over them. See heh, Katherine? Sally and Darrell accept Mary-Lou and take her on a friend. She likes Daphne because of her charming looks and ways. Eventually becomes one of school's biggest successes and leaves to train as nurse at Great Ormond Street Hospital.