Since we call her Sister, we dedicated the song Hey Soul Sister by Train to our youngest! She loves it, and I have it downloaded to my phone. She has her own play list on my cell phone, and she asks me daily to play her song. She has gotten to a point that she even knows some of the lyrics and will not allow me to sing along because she wants to do it by herself now.
http://www.metrolyrics.com/hey-soul-sister-lyrics-train.html