How about a version of
"Away In A Manger" without the the dotted rhythms! If further simplification is needed, have the student omit the left hand block chords.
Click the link for the free PDF of sheet music:
https://drive.google.com/file/d/0B3A_oLvMRe-cRDdxbllBYlJBUDA/view?usp=sharing