Julia

Julia is an elderly woman who wears a sparkly gold dress and has white hair that she wears up.

She arrived at the school bingo and it was her first time playing and she and Nick tried to cheat by sticking numbers on their cards, but Dirty Bertie caught them.

Trivia

 * Know-it-all Nick confirmed that she was his grandmother, therefore her surname might be "Payne", but only if she changed her name and is married to Nick's father's father.