Premise: Margaret Bryan, Baroness Bryan (c. 1468 – c. 1551/52) was Lady Governess to Henry VIII's children: Princess Mary, Princess Elizabeth, Henry FitzRoy and Prince Edward. The position of Lady Governess in her day resembled less that of the popular modern idea of a governess, more that of a nanny.
Hypothesis: Henry VIII's four children were looked after primarily by a Baroness, namely Lady Governess Margaret Bryan,