Hi Sandra!
Thanks for your question and for visiting the Disney Parks Moms Panel!!
I think you will notice some changes from the last time you visited
Walt Disney World Resort. Especially on the side of
Magic Kingdom that you are referring to. Back in the day, the northeast corner of Magic Kingdom was, in fact, home to Mickey's Toontown Fair, where you could find not only the Big Cheese's house, but Minnie's as well. After its closing in 2011, the area was re-themed as part of the New Fantasyland Expansion. In place of Toontown Fair rose Storybook Circus, a Dumbo inspired addition to the "land."
The train stop that you reference DOES still exist, but at this time the
Walt Disney World Railroad is closed to allow for the construction of a new and exciting TRON rollercoaster attraction over by Space Mountain. A re-opening date has not yet been announced.
I hope this helps and I wish you a Magical return trip!!
Chris