After poisoning her father and framing it as a heart attack, Vera is made queen by the Rite of Noble Choice, having been her father's favored for the position. She would be only 19 at the time of coronation.
The majority of the public would go on to view Vera as a grieving daughter that would, surely and dutifully, carry the legacy of King Frederick. Few suspected she had a hand in his death knowing that she had a guarantee in the throne.