Actually, is it only the female doing this? She could be trying to get everything out of the bowl because she wants to lay an egg (There needn't be a male present for this, but if there is, that just makes it all the more likly).
However my bird has done this forever. He's got three bowls - one for seeds, one for pellets, one more veggies. When the veggie bowl is not being used I put it back in the cage anyway and he will just.. lay in it. And duck down trying to hide, or nibble on the edges, playing, really. If that bowl isn't in there he will kick everything out of his pellet bowl to do it in that one, just lay there and kick like a dog. When he can no longer kick the little bit left out he starts trying to turn the bowl over by grabbing it with his beak, usually it falls to the floor with a loud bang.. and then he goes down there to play with it. He's done this for as long as I can remember. I would reccomend either getting a bowl she can have all the time (yes, just as a toy... you can spend 13 dollars on an all-out looking toy and they wont touch it, but give them a 50 cent clip on bowl...), or, looking into the possiblity that she may be wanting to lay eggs. If this just started that could be it but if it's gone on for weeks or month, she is either entertaining herself or she hates the food (If she eats it, that isn't it - they are not like dogs and will not eat something they hate.)