If you're talking about TS, she can share with you unless it's a 1) buffet, 2) all you can eat family style restaurant, 3) fixed price restaurant like CRT or Akershus, 4) dinner show, or 5) Via Napoli. And yes, you can use her child credit at other meals.
Thanks! We have are planning to eat at chefs and know that 4 meals for 4 adults/1 child is plenty.