Duty

https://commons.wikimedia.org/wiki/File:Queen_Mary_with_Princess_Elizabeth_and_Margaret.jpg

In 1936 the Princess learnt that their father had become king. Margaret Rose asked her sister, ‘Does that mean you will have to be the next queen?’ ‘Yes, some day’, replied Elizabeth. ‘Poor you!’ came the response.

— Lucinda Hawksley, Elizabeth Revealed: 500 Facts About the Queen and Her World, 2018