Whatever she wants, she gets
In fact, if she wants to make an official decree that makes it law for the following kings and queens to stick to this tradition, she can! After all, she’s the Queen of England, and she can do whatever she wants and get away with it. She’s in charge of an entire nation and is considered a crucial figure to millions of people across the world. She’s allowed to create and maintain her own traditions, right?
Keeping the Christmas spirit alive until early February in remembrance of her late father is just one of the things she does during these festive times.