Do you know of an HBO cartoon short that was made by Harvard University about two little girls playing in their nursery with original voices and put to a cartoon? It was broadcast circa 1980's. Any help in finding this would be wonderful!

John and Faith Hubley created several short films based on recorded conversations of their children.

Moonbird (1959)
Moonbird (1959) - IMDb (http://www.imdb.com/title/tt0053080/)

This Oscar-winning cartoon is on YouTube:
https://www.youtube.com/watch?v=vTgma3KJuSw

Windy Day (1968)
Windy Day (1968) - IMDb (http://www.imdb.com/title/tt0063816/)

You can watch it on YouTube:
https://www.youtube.com/watch?v=cit6iUEEdyo

Cockaboody (1974)
Cockaboody (1974) - IMDb (http://www.imdb.com/title/tt0251027/)

Yes, it's on YouTube:
https://www.youtube.com/watch?v=NSFKjfQolgY

You might enjoy their other works, including the lengthier cartoon "Dig" (1973):
https://www.youtube.com/watch?v=d6QIDwhVMkc

The Hubleys did a number of projects; when he died, Faith Hubley continued as an animator.