They had found the seashells in Roxas' pocket. Or seashell, rather. The rest were broken shards. Riku let her have it, pressing it into her hand when DiZ wasn't looking.
They didn't understand why he would have seashells with him. They had forgotten already.
She still remembered, but it was getting harder to. It was slipping away, everything that had to do with her. (Xion. The memory of the way she put her hood down. The image of her faint smile. The sound of her voice.)
She ran her fingers over the seashell a few times, before placing it with the drawings she had hidden away. It felt like it belonged there. She stood there, looking at them for a long while.