There is literally no point for a Queen or concubine, bringing balance is the last thing that having one of the two will bring. Her and and anyone in her family will be a threat to the still cementing throne. Think about it, the child she would bare would be nothing more than her and her family's bargaining chip among the royal court. Courtiers would be up to shady shit and do whatever her whim cause of her heir baring coochie.
This is literally heartbreaking to watch, but I can't look away.