The same reason she's done some other things, T. That is why you are being told to be careful and take it slowly. We are all hoping this MC will be instrumental in giving both of you the tools you need, but it is much too early to tell if your W will continue this way or how effective the sessions will be for her.
It is really hard to change lifelong behaviors. It can be done, but it takes a lot of desire, effort, and determination. I believe you have what it takes. I hope your W does.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!