lady-in-waiting:
(plural: ‘ladies-in-waiting’; for the right pronunciation, please click here)
(mostly in British English usage) a lady who attends/stays with a queen or princess, especially at a traditional ceremony,

a lady-in-waiting with the Queen
When my granddaughter, Nikki, wrote to Her Majesty The Queen about an idea to solve the housing problem in England, a lady-in-waiting, on behalf of Her Majesty, promptly replied saying that the Queen would like to consider her wonderful suggestion!
It is customary that every Queen or Princess must have more than one lady-in-waiting to look after Her Majesty’s or Highness’s day to day affairs.
The ladies-in-waiting are usually from the friends and relatives of a female royal member who know all the social and foreign etiquettes and current styles.
