I feel like they might have printed the songs before finalizing the setlist, notice Pie Jesu is also on the list, but was never performed on tour. They might have intended to include those two songs, but just couldn't find a place in the show for them. During the 2011 Songs From The Heart Tour, Chloe sang When You Believe in her second act pink dress, then had a quick change during the first part of At The Ceili, and entered during Mairead's solo before her part. See these videos for reference.
https://www.youtube.com/watch?v=vF5HkFofEC0https://www.youtube.com/watch?v=IPKSAhRYPuw