You did the right thing, my friend. All she has done right now is made an appointment to go to rehab. What you see in her actions moving forward will tell you how serious she is about recovery. In the meantime, you have upheld your (very healthy) boundaries around your own self-care. Good for you.
You don't have to worry about what happens if/when she comes back from rehab until that happens, and by then I am guessing both of you will be in very different mind sets than you are right now. Again, that's if she goes.
Keep reading, keep posting, you've found a very supportive place here.