I care for a two and a half year old boy that is the same way, always asking to eat. He doesn't have a problem with the actual eating though. In fact, I have posted about "cutting him off". He is not starved, thats for sure.
But all day long with the "X's HUN-reeeee" (he always refers to himself in third person). Staring at my fridge and cupboard. I asked mom and she says he's the same at home.
I don't know. Do you think she might be bored? I've been a bored eater for as long as I can remember. Or maybe she's coming down with a tummy bug? If she's getting crampy tummies, maybe she THINKS she is hungry. My girls just had a nasty virus that caused stomach pains that came and went.