Hi Diane!
Thank you for visiting the Moms Panel!
Typically, all the theme parks are busiest at the weekend, followed by Thursday and Friday. To make the best use of your time at any of the parks at this time of year, I would suggest arriving as early as you can, so you are among the first into the park, when it could be quieter at the start of the day.
If you can use the Extra Magic Hours (when the parks are open for an hour before usual opening time, or for a few hours after the park closes, available to Walt Disney World Resort hotel guests only) this will also help to maximise your time at the parks.
Check the park calendars to see when Extra Magic Hours are operating during your visit:
Magic Kingdom Epcot Hollywood Studios Animal Kingdom
If you have any other questions, please come back and ask me - I would be happy to help you plan your magical vacation!