Reason #1 - Nature based religion

The first reason for why you should have your kids watch it is because, it demonstrates, very nicely, the Powhatan's nature based religion.  Which is where their religion is based off of nature such as, everything has a spirit. They went as far as implementing a talking tree as one of the characters and it was a spirit tree. Also, as far as to having Pocahontas mention it in the movie, she said, that everything had a spirit. Now, based on those facts and examples, you can see why that is my first reason.
Pocahontas talking to grand mother willow
Jamestown John Rolfe John Smith Pocahontas Powhatans Starving Time