Who is Miss Marguerite Parsons from The Man Who Listens to Horses and what is their importance?

Miss Marguerite Parsons is an important influence during Monty's early life. She is a tutor with a 1940s hairstyle and deep brown eyes. Monty describes her as a "woman of character." Parsons serves as both a babysitter and teacher for Monty, and he loves and respects her in return. She with Monty until he is fourteen, and she is noted to be the only person who is sympathetic toward him.