Trouble with advisor in final Ph.D. phase
I'm sorry to hear about your situation. I had to change my Ph.D. advisor (and I'm very glad I did), but it was in the early phase of my dissertation process. I'm quite surprised by your "discovery" about a potential of your advisor not caring about your career. Firstly, it is unlikely (why would she "tolerate" you for 5+ years then?). Secondly, if your advisor would truly not care about your career, it should have been pretty clear early in your collaboration, so either your assumption is not true, or you paid no attention to this aspect at all, which is quite difficult to believe in.

Anyway, in regard to your potential actions. I strongly recommend you to consider all possibilities to avoid changing your advisor, considering how far are you in the program. Changing an advisor is not only a administrative / logistical nightmare, but, if it would require you to start your research from the scratch or almost from the scratch, it would be extremely depressing, to say the least.

If you could save five years of work and life by defending your dissertation and graduating, even if parting with your advisor not very amicably, I would say that it is worth a serious consideration. The two obvious dangers in this case would be: 1) being able to defend dissertation successfully; 2) potential problems with obtaining a recommendation letter from your advisor (she could either decline, or give a negative or not so positive one). The second aspect is quite important, as your postgraduate applications, not listing your dissertation advisor as a referee, might raise quite a lot of eyebrows, with potentially negative consequences in regard to your postdoctoral offers / career.

You have to carefully think about all these (and other) aspects, consider feedback from people here and your own environment, but, ultimately, only you can decide the best course of action, based on various details, known to you only, as well as your gut feeling, as some new research suggests.

Regardless of what you decide on the subject and how you part with your advisor, I wish you to successfully graduate and achieve your professional and personal goals in the future. Be strong in staying your courses, but flexible in ways of reaching your destinations. Or, as Lao Tzu has said,


  Nothing is softer or more flexible than water, yet nothing can resist
  it.