To put it simply, a lady in waiting is an attendant to a female member of the Royal Family and she is usually the wife or daughter of a peer but could just be a close friend or cousin of the royal she is attending. Her duties are to act as a companion and to help the Royal during her day-to-day duties. On occasions she would be involved in replying to non-official correspondence and diary events.
When Queen Elizabeth died, it was announced that The Queen Consort, Queen Camilla, would not have ladies in waiting but instead she would be attended by queen’s companions, also that the role would be much more informal in that they would not be involved in the administrative tasks usually covered by ladies in waiting.
The King also announced in September 2022 that the late Queen’s ladies in waiting would be retained, those that were not intending to retire, and would be known as ladies of the household. Their main duty would be to help in hosting events at Buckingham Palace.
Image, top: Portrait of an Unknown Lady, said to be Jane Dormer, Duchess of Feria, and lady-in-waiting to Queen Mary I