Is she broody?

I know hybrids dont normally go broody but i have a black rock who im having to lift off eggs every day for the past 3 days. She spends hours just sitting, or could there be another reason for her sitting like this?

my blackrock went broody last year and hatched me some lovely chicks  . You will know if she is proper broody as she will fluff up and make a growling noise when you go to lift her off the eggs 

are the eggs likely to be fertile? If yes do you want her to hatch any? if you do want to hatch what will you do with the cockerels born? If the eggs are infertile then keep lifting her off them severel times a day - or wait until the others have laid and close the nest box up. It is a hard cycle to break and can take weeks 

If mine is in there too long i put her outside , a few grains of corn will soften her up and stop her p-karking for 20 minutes solid.

OK, I'm going to show my ignorance here: does it matter if a hen goes broody, especially if the eggs won't hatch?