Who is Miss Moneypenny from You Only Live Twice and what is their importance?

Miss Moneypenny is M's secretary who seems to have love-hate feelings where Bond is concerned. Her demeanor when she is first mentioned in Curtains for Bond? is hostile, but it changes in the next chapter, The Impossible Mission. After Bond's meeting with M, he kisses her on the cheek. She brightens right up, and then he tells her to contact Mary Goodnight as he plans to take her out for dinner to celebrate. Miss Moneypenny seems to be in on what M is up to.