Lady Elizabeth Bowes-Lyon was the daughter of the Earl and Countess of Strathmore. Would you say that her background of high position and privilege was good training for her role of Queen Consort?
I think she certainly had an idea of service - to the staff and workers on her fathers estates, for example. And during WW1 the family's Glamis Castle was turned into a hospital for wounded soldiers and there are pictures of her with the soldiers. I think she was too young to have trained as a proper nurse but she helped there. And some letters that soldiers wrote to her were published IIRC