Short for her age of eleven, Ida is the great-niece of Dr. Maude Biggin. Ida is confident and brave, and is the leader of the trio of friends that consist of herself, Oskar, and Ping. She has been invited to Green Knowe for the summer by her Aunt Maude, to keep Oskar and Ping company. The three of them become friends quickly, and share the attic room in the manor, from which they can see the grounds off the manor, and the river.
Ida is also gentle and kind, as well as protective and watchful. She takes great care, for example, to watch over Oskar when he is the size of a field mouse. Ida and the others know how very much Dr. Biggin wants to find a giant, so they plant a giant tooth in the gravel path, and bring Dr. Biggin to the circus, where Terak is performing.
