This child is gonna be the death of me

My 6 yr old that is. We went out to dinner for burgers. She only wanted to eat 1 1/2 chicken tenders, she was "too full" to eat her fries. Oh but she wanted a giant cookie, of course she didn't get it. Come home around 6 and I let them play outside with the neighbors kids, I had to go out for a min and their step dad didn't tell them to come inside. So at 8 when I got back I tell them to come inside, go straight to the shower and bedtime cause there's school tomorrow. Well NOW she decides she is starving, but when she was outside playing she was fine. No problems! I tell her to go straight for the shower because she was es dinner and as usual she threw it away. That bedtime is not the time to tell me she's hungry. And she does the same thing every single night!