Clara is a student at Pokey Oaks Kindergarten. She is a non-speaking character most of the time, but she does have a line in the episode Keen on Keane, where she was voiced by Rachael MacFarlane, who later became best known as the voice of Numbuh 362 on Codename: Kids Next Door and Mindy and Eris on The Grim Adventures of Billy & Mandy.
Ms. Keane mentions what her name is when thanking her for her gift in Twas the Fight Before Christmas.