For 'Valiant' fans.

Has anyone noticed that Val and Luis from ヒイラギ, ホリー Blacks book 'Valiant' are in City of Bones, for about four lines?
I was 読書 it the other 日 (for the fourth time I must admit) and just noticed it, rembering that Cassandra and ヒイラギ, ホリー are friends.
Am I the only one who saw it?