Hey sryinga Welcome to BYC!
That is a tough call without more information.
How old is she?
What breed?
What is your current climate? Are you in winter or summer?
A broody hen on the nest will usually puff up in a threatening manner or even peck you. If you put an egg in front of her on the nest she will usually use her beak to roll it under her and snuggle onto it.
A broody hen will usually get up one or two times a day for something to eat and drink, stretch her legs, drop her huge broody poop and then return to the nest. She may be doing this but you have not seen her?
However, if she is sick, she would probably be lethargic and not protective of the nest and not really interested in an egg. She could be egg bound.
Does she appear to be straining at all?
Is she doing anything else out of the ordinary that might help us determine if she is broody or unwell?