For what ever reason the eggs were either not fertile or viable. It is quite common for hens to consume non-viable or infertile eggs. Tell us, is she in a place where no other hen can interact with her?It is likely hen herself consumed missing eggs. If she is now four days overdo, then initiate procedure to break her of broody cycle or give her newly hatched chicks.
The reason I asked is because sometimes two hen can get into FIGHT over which hen a nest belongs to. In these cases the hens don't stop ahead of time to think about what is going to happen to their eggs.Yes she is separate from the rest
so no other chickens can get at