Amneris, Do Re Mi or many other R&H songs would be appropriate. R&H was my first introduction to musicals and I was younger than 5 when I was learning those songs. Do Re Mi is also in a lot of childrens' music books. I recall my sister having a toy piano with a songbook and Do Re Mi was one of the songs. Also, when I was little I had a record (yes a RECORD) called "Bob Sings". It was Bob from Sesame Street singing and several of the songs were Broadway. Do Re Mi, Getting To Know You, I Whistle a Happy Tune, Good Morning, Starshine, and Edlweiss.
Another Good one is "Heart" from Damn Yankees. That, along wuth I Whistle a Happy Tune, and Getting to Know You might be ideal because not only are they "easy" but they have good messages.
"All our dreams can come true -- if we have the courage to pursue them." -- Walt Disney
We must have different Gods. My God said "do to others what you would have them do to you". Your God seems to have said "My Way or the Highway".