Eating habit

Shi-Shi's eating habit is not stable. Sometimes she eats a lot, just as much as adults do, but sometimes she eats only bites, just as little as a little mouse. Mama has no idea about what makes her eating habit stable. Her daily schedule is alway the same, going to a music class or an art class in the morning, taking a nap for two hours, going to a park later afternoon, and having a dinner at around 7:00pm. It happens to small children, and shouldn't be worried, though, when she doesn't eat much, she leaves a table so fast and comes to papa or mama to play and papa and mama can't relax while having dinner:(