Hi there, Zane!
Once the meals have been delivered to the table (or you have picked them up from the Quick Service counter), they are free to be eaten as you like. I have shared, divided, and removed any number of items from the plates of my traveling party at various times; as long as there are no modifications to your
Disney Dining Plan, there should be no issue in dividing up the food as you'd like.
If your concern is that your two-year-old will be upset with the presentation of the food, it might be worthwhile to bring some "distracters" to table time. Maybe before your trip, you can find some fun coloring pages to print out and bring with crayons for the little one to color. You could also consider bringing with you small packages of pretzels, chips, etc. to add to your little one's meals.
Some of the meals are served in plastic plates shaped like Mickey Mouse. You might ask the Cast Member for a spare empty plate on which you can there serve your little one. That seems like a very reasonable request. Incidentally, these plates are disposable, and are not meant to be taken with you, so your older children will not be receiving special souvenirs that your little one will not (check with any of your
signature dining experiences to confirm that is also applicable).
If you'd like, drop me a line and let me know where you'll be dining. From there, I can give you some further suggestions on minimizing the differences.
Have a great time!
See you later, celebrator,
-Deborah B.