Mary died at Westhorpe Hall, Westhorpe, Suffolk on 25 June 1533, and was initially buried at the abbey at Bury St Edmunds, Suffolk. Her body was moved to nearby St. Mary's Church, also in Bury St Edmunds, when the abbey was destroyed during the Dissolution of the Monasteries. Her husband soon married their son's fiancée, who was also their ward, fourteen-year-old Catherine Willoughby, by whom he had two sons.
Her relationship with her brother Henry VIII had turned sour over his sought annulment of his marriage to Catherine of Aragon. Whom Mary had become close with. She strongly disliked Anne Boleyn, they had previously met in France when Mary married old king Louis XII.
After Louis died she secretly married the ladies man Charles Brandon. They had three children together, and Mary was also grandmother of the executed Lady Jane Grey. She spent most of her time in the country estate of Westhorpe Hall in Suffolk