In Kathleen path Mc won't have much resistance to being drugged and if he does resist there is big Warren to subdue him.
In Kath path, Kath is not interested roughly forcing MC to do something with Warden help or smth, cause there is no need in that, she Just guides his mind smoothly and more gently, MC at the end of current update is not resisting her and already working on his "moral shift" willingly
So, I think Kath Will not try risking to lose MC by forcing speed up the process to much.
edit: c'mon guys, she's evil sadistic hug but still character with Special stat "trust", it's easy to noticed, she had already changed her acting towards MC quite a lot
I dunno, maybe she wants to be his "Mother with benefits" in future