the queen fed her enemies to her dragons

This is an example of metonymy:

It’s metonymy when you use a person’s name to refer to the works by that person, as when you say “I had to read Hemingway for a class” when you really mean “I had to read a work by Hemingway for a class.” Another straightforward example is when you use a city’s name to refer to its team, as when you say “Houston was ahead by six points.”

Merriam-Webster

Or possibly synecdoche (sources seem to differ in the exact definition of each):

A figure of speech in which a part is made to represent the whole or vice versa, as in England lost by six wickets

Oxford Dictionary