I saw a film when I was a kid about three orphaned children. They were allowed to create a "grandmother", who showed up in a sarchophagus (sic) and could pour chocolate milk out of her finger. Is this Ray Bradbury? and what is the name of the story?

The name of the film is The Electric Grandmother.

The short story it is based on is called I Sing the Body Electric.

This brings the lights back on in an old post topic:
http://www.dailymail.co.uk/sci...chines-90-years.html