Question:  Katherine Stanhope, Countess of Chesterfield was the governess and confidante of this Princess who was married to who 
Sentence (from "Mary, Princess Royal and Princess of Orange"): Mary, Princess Royal (Mary Henrietta; 4 November 1631 – 24 December 1660) was Princess of Orange and Countess of Nassau by marriage to Prince William II, and co-regent for her son during his minority as Sovereign Prince of Orange from 1651 to 1660.
Relevant evidence: Yes