J.M.
How about these? I worry about jazzy if the audience can't recognize the song. It has to be familiar enough that the audience can get into it.
Nelly Furtado "I'm Like a Bird"
Natasha Bedingfield "Unwritten"
Pink "Perfect"
Cyndi Lauper "Time After Time"
Duffy "Mercy"
Adele "Pounding Pavements" or "Rolling in the Deep"
I love musical numbers, so here are a few of my favorites:
Les Miserables "On My Own"
Wicked "Defying Gravity" (incredibly difficult)
Phantom of the Opera "Think of Me"
Guys & Dolls "If I Were a Bell"
Good luck to her! BTW, my BIL is from Decorah. It is beautiful!