It sounds like she already has one foot in the door to be honest. my guess would be she has felt like this for a long time and she has reached boiling point. She is trying to blame you for things not moving in the direction that she wants fast enough because she is frustrated.
I would say something like 'You have to do what you have to do. Your right, i dont own you. If you want to do this we will just have to wait and see if i am still around at the end of it. Its a shame you have gone about this in the way you have, I dont feel I would have treated you this way'. She wont be able to accuse you of trying to own her or tell her what to do and when you create distance from someone (i.e step back a bit) that supposedly loves you they will try and fill it.