Xion watches as the charm is pulled out. She knows what it is, or at least, what it represents. She's seen it in Sora's memories, though this one is not made of the Thalassa shells, something tells her that it will work just the same.
"I'm sure you'll find them one day soon." It's true, Xion believes that this woman will no doubt return to those she cares about soon. "Those charms. They're used for good luck and a safe journey. And also to keep friends tied together." However, she doesn't comment on the fact that she believes that she'll never see Roxas or Axel again. She's needed here, and her duty to Sora.. It was something that had to be prioritized above her own selfish needs to see her best friends again.