Lady Cathleen Blanche Lily Hudson (née Eliot; 29 July 1921 – 5 October 1994), also known as Lady Cathleen Seyfried, was a British noble. She was the younger daughter of John Granville Cornwallis Eliot, 6th Earl of St Germans and Lady Blanche Linnie Somerset, daughter of the 9th Duke of Beaufort. She was the mother of the present Baron Herbert.
Her father died from pneumonia on 22 March 1922, whilst recuperating in South Africa following a riding accident, leaving issue two daughters. His earldom and associated titles thus passed to his first cousin. Her mother, the widowed Countess, remarried George Francis Valentine Scott Douglas and had a son James Louis Fitzroy Scott Douglas (1930-1969), later Sir James Scott Douglas, Bt [1] by her second husband; this half-brother died unmarried.