She didn't really have a chance to do much of anything before Dean was shooting, complaining and grabbing his knife. She hadn't meant for him to stand right in front of her! She wasn't exactly helpless.
She huffed and rolled her eyes then put her hands on Dean's shoulders, leaning up to hiss in his ear. "When you hear me say weird shit shut your eyes. Don't open them until...well you'll know when, but start firing immediately."
She didn't wait for agreement, just let go of Dean's shoulders and thrust her hands out to the sides, palms forwards. Iron was the only thing that could hurt these bastards, but she could make them a little more vulnerable.
"nuS tsrub." She hoped Dean took her at her word because pure sunlight flashed from the palms of her hands at the oncoming changelings. Full fae it wouldn't have had any affect, but with changelings, it stripped them of their human seeming leaving behind ugly, knobby flesh that was very vulnerable to bullets.