Hi Della!
Thanks for your question. You win "Aunt of the Year" for taking your nephew to his first
Disney World trip! I can only imagine the joy you'll bring to his face, and how captivated he will be spending time both with his family as well as his extended Disney family (Mickey, Minnie, Donald, Goofy, Pluto, and the remaining characters and Cast Members).
Spring is always tricky at Disney, especially since different school districts around the country take Spring Break at different times during Spring season. It's hard to give you the best week, but if you had to choose, I would consider going one of the weeks during the month of March. I can say many schools typically take their Spring Break somewhere near Easter holiday weekend, so you may want to avoid the weeks of April 6th or April 13th (Easter 2020 is on April 12th). To be honest, the first week of April - perhaps mid-August is peak season for Disney, so sometime in March may be your best bet.
Hope you and your nephew have a magical time at
Disney! Be sure to capture all the
amazing attractions tailored towards children of his age range and height!
Have a good one!
Terry