What's a good slow song for a 10 y/o girl with a powerful voice?

My other niece ( i have been talking a lot about my family a lot lately, haha lol(: ) sings and she sang Better in Time by leona lewis and got 2nd place in her local talent show, nd sang grenade by bruno mars and got 3rd place. she has the potential and a VERY powerful voice and is capable of so much, we are thinking about singing I will always love you by Whitney Houston ( she sings it very well ) and she an hit high notes and long notes, so any suggestions as to what she can sing?? Thank you(: