The difference between Cheney, Kinzinger, Flake, and Corker is that they broke hard and with finality from Trump, and Nikki has not, or at least not yet. Nikki may be a woman, but when it comes to Trump, she is no Liz Cheney.
I grant that Trump might yet destroy her completely, as you appear to predict, and you don't have to grant at all that there's any chance that she comes back to Trump and he gives her some role in his administration. But just because you don't, that doesn't mean it can't happen. I think it could, I think she's trying, I bet Trump is at least listening, and who knows what will finally come from that.