She doesn't do anything.

She slaps his hand away, "I've got it." She snaps, she gently takes Lin's arm, "I feel really bad that your in the middle of all of this, but I still don't understand why you do nothing." She mutters, beginning to sprint away, dragging Lin behind her.

(Ping)

She just lets herself be dragged.

"Helloooooooo." Puck's voice echoed farther down the cavern. "Sorry, ugly, wrong me! Keep going, and I'm sure you'll get it right next time!"
Ironhorse looked up from stomping a fake Puck into the ground, crimson eyes blazing with hate. He was about to charge another Puck when one of the gremlins spotted them running away and gave a yelp of alarm. Ironhorse whirled, eyes flaring as they settled on them. Ash muttered a curse. With a bellow and a blast of flame from its nostrils, it charged, bearing down on them like the steam engine it was named for. Ash drew his sword and flung a shower of ice shards at the monster. They shattered harmlessly on its armored hide, doing nothing but enraging it further. As the roaring, flaming bulk of metal descended, Ash shoved the girls out of the way and dove forward, the flailing hooves missing him by inches. Rolling to his feet behind the monster, he cut at its flank, but Ironhorse plunged its head down and kicked Ash in the ribs. There was a sickening crack, and Ash was hurled away, crumpling to the floor in a heap.
A screaming flock of ravens descended on Ironhorse before it could stomp Ash into the ground. They swirled around its head, pecking and clawing, and Ironhorse roared as it lashed out at the flock, blasting them into cindery buts. Ash staggered to his feet as Puck appeared beside them.
"Time to go," he announced cheerfully. "Prince, either keep up or get left behind. We're leaving."

She glares at Puck then looks at Ash, "Thanks." She says, looking back at the distracted Ironhorse.

Lin stays blank-faced the entire time.

Puck ran through the caverns, slipping on ice and slush, the insane roars of Ironhorse and the hissing of the gremlins on their heels. Ash somehow managed to keep up. A fuzzy gray shape bounded towards them, tail held high. "You found her," Grimalkin said, stopping to glare at Puck. "Idiot. I told you not to fight the horse thing."
"Can't talk now, little busy at the moment!" Puck gasped as they tore past the feline, continuing down the tunnel. The mouth of the cave was visible

(So what powers can Claire have?)

She stays ahead of the others, at a full sprint as she swiftly tears through the mouth of the cave and continues on.

She just stares at the sky.