This song I remember very well. My mom sang it to me. Here are the words...

In a yard where children were playing games one day.
A little girl sat sadly, watching as they played.
She asked them if she could play too, but they said she'd spoil their fun.
The little girl went home to tell her troubles to...
(Chorus) mommy when I go to heaven, will the angels let me play?
Or will they say I'd spoil their fun, and am I baby too?
Mommy when I go to heaven, will the angels let me play?
Or will they say I'd spoil their fun and Am a baby too.