Groom dancing with his sisters; Song Recommendations?

My fiances mother passed away in May of this year from cancer. He wants to dance with his two sisters in place of the Mother and Son dance. He's having a hard time thinking about it too much, so he hasn't picked a song. I want to make a list of songs that either honor his mothers passing or that symbolizes the strong bond he has with his siblings. If you guys have any song recommendations, it would be so much appreciated. This is such a hard task for both of us and any ideas would be so helpful.