Final answer:
Without specific context or knowing which literary work references Miles and the governess, it's not possible to predict what Miles will disclose. Typically, a character in this position might share secrets or confessions that can alter the narrative's direction or deepen understanding of the characters involved.
Step-by-step explanation:
"Miles is going to tell the governess everything she wishes to know. What do you suppose he will tell her?", they are referring to a character's interaction from a piece of literature, and it is likely they are exploring the character’s thoughts, feelings, motivations, or actions within the context of the story. Given the texts provided, however, it is not clear which specific literary work or character named Miles the student is referencing. Without the specific context, it's not possible to accurately predict what Miles will tell the governess. In the context of literature, a governess is a woman employed to educate children in a private household, and characters in these roles are often involved in significant dramatic plotlines concerning family secrets or personal drama.