She managed to send Navier away, she thought Sovieshu's attention only hers now. So why did he cast her away?

When she got news of him getting a concubine, she had to see you. And to her horror you looked like a queen, laughing graciously on the emperor's lap.

Not only that, but you were holding her child! The one Sovieshu wouldn't let her see, he was letting you act like her daughter's mother!

"You must be his majesty's new toy!" Her words venomous.