Oh, now I see what you're talking about. I definitely saw her firing up her powers right before the impact, but the way it looked to me was that her powers were ineffective. That is, it looked to me as though she were trying to stop the crash and then failing. Which I thought was sort of the point. I thought you meant that she's shown using her powers after the crash, indicating that she must have survived the crash.
Another question occurs to me: if Dr. Polaris knew that Aura survived, shouldn't Repulse, who is, after all, a figment of Polaris' imagination, also know that? And if so, why would Repulse leave the scene with Aura still alive? Other than the fact that Repulse, is, after all, insane.