Lady Rhondda was born on 12 June 1883 in Bayswater, London, England, UK. She was married to Humphrey Mackworth. She died on 20 July 1958 in London, England, UK.
She and her father were sent by David Lloyd George to the United States to arrange the supply of munitions for the British armed forces during World War I. On their way home, their ship, the RMS Lusitania, was torpedoed by a German submarine. They were among the 764 people who survived the attack.