Ladies in Waiting - Terminology
This link tells us that the King is keeping three of the late Queen's Ladies in Waiting to "assist His Majesty when hosting formal occasions at Buckingham Palace." They are to be known as Ladies of the Household. I did not recall seeing that title before but it is used in Royal Service Vol II 2001 by four authors. They say "Today the Ladies of the Household are the Mistress of the Robes, the Ladies of the Bedchamber and the Women of the Bedchamber, with such Extra Ladies and Extra Women as may from time to time be required." Also "None of the Ladies in Waiting receives a salary..." so I think we have simply got into a habit of referring to them all as Ladies in Waiting.