M.M.
Sounds like a growth spurt to me, at that age. Is she rolling over yet? Either one or both ways?
My son did this when he was learning to roll, and it lasted for about 2 weeks. (He learned to roll both ways at that point).
If she's eating that much, chances are that she needs it and may be approaching a milestone.
I'd wait it out for a week or two and see what happens. She'll eat what she needs for this point in time, and then go back to "normal".