I'm in the middle on this one.
The BigTex approach definitely has merit if she's worth keeping in the first place, and I would have said the same a year ago, but...
time is too short to fuck around with trying to wake up someone who should already be smart enough, and who has heard it from you long enough, to be very well informed.
At some point, it comes down to her assessment of your (and your sources) credibility. How right do you have to be and for how long before the person closest to you finally pays attention to what you are saying and takes it seriously? If she's not willing to open her eyes, despite all objective truth and evidence that you try to present, then kick her ass to the curb. She will be an anchor that will drown you in the early stages of die-off if you don't.
And if you do not have children, get out of the relationship PRONTO if she chooses denial and clinging to a literally dead-end lifestyle over your attempts to help both of you.
It took me a while to really get my wife to absorb all this, and I still wonder exactly the extent of her comprehension of the impending doom, but she's 100% on board with all my planning and preps. She's changed more, learned more, and grown more as a person in the last two years than in her whole life. It took some effort, but everything I've been telling her has been manifesting itself in more direct, obvious and tangible ways (and on a daily basis - now), which has also helped wake her up.
Peak oil is here, now.

This is no longer an academic exercise for you or her. You need a teammate, not a sparring partner. Major arguments should not occur over whether or not to prep a "lifeboat" after you know the ship is already sinking.
Talk to her about the TITANIC a bit more - it really is a great analogy for our great hubris, deadly denial, and group panic. As is the example of so many Holocaust victims, even to the point of reaching the "showers"...