[9] Catherine went on to be appointed Maid of Honour to both Anne of Cleves, in November 1539, and Katherine Howard, who were the fourth and fifth wives of Henry VIII.

For the first ten years of the reign, Lady Catherine combined the most senior post among the ladies-in-waiting with motherhood to more than a dozen children.

At court, Catherine was acknowledged as the queen's favourite among her first cousins, and Elizabeth's lack of other female relatives to whom she felt close may be adequate to explain this favoured position.

Catherine's epitaph reads:The Right Honourable Lady Catherine Knollys, chief Lady of the Queen's Majesty's Bedchamber, and Wife to Sir Francis Knollys, Knight, Treasurer of Her Highnesses Houshold, departed this Life the Fifteenth of January, 1568, at Hampton-Court, and was honourably buried in the Floor of this Chapel.

Carey is also a character in Gregory's The Boleyn Inheritance, where she is sent to the royal court during the time of Queens Anne of Cleves and Katherine Howard, and in The Virgin's Lover, where, as the mother of the seventeen-year-old Lettice Knollys, she is among Elizabeth I's closest companions.

In Henry VIII's Wives by Alison Prince, the book's narrator has a friend, Catherine "Kitty" Carey, whose father died of sweating sickness and whose mother is Mary Boleyn.