Queen (Y/N)

You were a peasant girl who met the royal family only once. Apparently you struck a liking with their son/daughter/child. You were poor and your family hated you. You did have a little brother. One day, the royal family is killed. The son is left and the aunt is too. The son was to become the king but in their wills you were put as the one to inherit the crown. The former royal family are perplexed and forced to live as normal people. You become the queen