King Simon and Queen Helena are married and they are also the king and queen of England. They sometimes don't see eye to eye on things.
In Stand and Unfold Yourself they are both seen standing together in front of Prince Robert's casket crying, but then an employee ruined the moment. Later in the episode they are seen at the dinner table and she's about to leave but the King gets mad and then tells the family that he is considering abolishing the monarchy. Queen Helena gets upset. Later on in the episode the queen and the king are discussing the reason why he is going to abolish the monarchy. He says that this was the reason why they lost Prince Robert and he doesn't want to risk another child because of the throne.
They don't have many scenes together in Infants of the Spring, but they were seen when they were talking about the garden party. King Simon gets upset because she is throwing a party when their son just died. He says that she is only throwing this party because Helena doesn't want the king to abolish the monarchy.
In We Are Pictures, or Mere Beasts, they still have trouble between each other. They continue to fight. This time is about being good parents to their children. The King gets upset at Helena because she took the location of Princess Eleanor's fashion show. Simon says that this was the only thing that Eleanor took seriously and Helena ruined it. In the end King Simon says the Queen before they go to bed that they should be better to their children because they won't always be a monarchy, but they will always be a family. Helena replies by saying that it's too late for that. Before they took the family photo they looked disappointed in one another.