She Thought through her wish before saying it out loud
"I Wish That Everyone except for himself and I believed him to be a girl, for the next month, Jon would not be able to tell them otherwise, but would know that he was a boy. I wish that he will not suspect the stone or myself of doing anything. and I wish that while everyone believes he is a girl, he will play along with anything anyone asks him to do that will encourage femininity."
Karyn Smiled to herself noting that the pictures of her and Jon now had Jon in particularly feminine clothing