Iris didn't want Kellan to take Joyce with him, because she knew what kind of fate he would make the girl to succumb to.
"Cane, please. Don't make him take her away to the palace," Iris cried.
But Cane said nothing, and waited until she was calm enough. "I can't promise you anything. There is no definite plan to stop him from taking the girl."
Right now, there were a lot of things going on, Cane was in the middle of his plot and he had to tread his path carefully. If he did something to prevent Kellan from taking the girl from his own orphanage, something he was used to, it would get his attention and the last thing Cane wanted when he was in the middle of the eye of the storm was to startle the snake in the bushes.
The risk was too high and there would be a lot at stake if he alerted Kellan he was against him, since he had a long plan ahead of him for that prince.