Her maternal grandparents were Thomas de Beauchamp, 11th Earl of Warwick and Katherine Mortimer, a daughter of Roger Mortimer, 1st Earl of March.

Through his paternal and maternal grandmothers, she was descended from Edward I and John, King of England respectively.

Katherine was married to Michael de la Pole, 2nd Earl of Suffolk in April 1383.

He was a son of Michael de la Pole, 1st Earl of Suffolk and Katherine Wingfield.

[1] They had the following issue, the eldest of whom would not be born until 1394, eleven years after their marriage: Michael died on 18 September 1415, from the flux.