Rebecca,
I love restaurant questions! I can practically taste the food, just typing about it!
So for the lasagna, you want to try out
Tutto Italia, which is located in the Italy pavilion at the Epcot World Showcase.
Your daughter will get the best all-around princess experience at
Restaurant Akershus, also in the Epcot World Showcase.
For Chinese you actually, again, need to stick in the Epcot World Showcase (surprise) and go to
Nine Dragons in the China pavilion.
Finally, for your 10-year old, there are a lot of choices for pizza, but not many are all that great frankly.
I love the flatbreads at
Mama Melrose (Hollywood Studios), and the pizzas at
Portobello (Downtown Disney) but they are probably not what he would call typical pizza. For something more traditional, he might simply like the pizza at Pizza Planet in Hollywood Studios or at the pizza window on the BoardWalk, even thought they are quick service, not table service restaurants.
Please send more requests, if you need them!
Have a magical (and delicious) vacation!