Cruel Reality (Princess! Reader x Prince! OC!)

Y/n is the beloved daughter of King William Hawkthornne the 9th. He rules over the English empire and would gladly do anything to protect his subjects. (Note: I am trying to be at least a little accurate when writing this. It's taking place in Medieval Times, so... yah." His lovely Queen, Annabel is your beloved mother. She is kind and caring, and just as stubborn as your father. They never sent you away to a manor to spend your days, and were never willing to deny you the throne. (Back then, women were seen as not fit to rule. Sorry! Just sticking with the history!) Lately, the Royal Council have been demanding they try to have a son, so the Royal Bloodline will stay pure. Your father was outraged! If he were to do such, he would be reducing you to no more than a commoner! Your father would not be having that. Instead, as his wise queen Annabel instructed, he asks all of England. "Would you, the Loyal people of the Great empire of England, rather me have a son, and shame our beloved princess, who has always treated you with true kindness and love? Or would you rather her marry a prince from our rival, France, and allow our beloved princess to continue a happy, love filled life?" Your subject rallied behind your king, and letters were sent out. You were to be married to Prince Adam of France at the age of 18. How will your story unfold?