We need to differentiate if she's truly egg bound, brooding, or ill. An egg bound hen might walk like a penguin and squat as if to lay frequently. You might see a distended lower abdomen as well. Here's more information for you in this regard: http://www.backyardchickens.com/a/egg-binding-symptoms-treatment-and-prevention
A broody hen may act aggressively toward you when approached, resist being moved, show a diminished appetite and have less frequent but more voluminous droppings. Here's more information for you in this regard: http://www.the-chicken-chick.com//search?q=caring+for+broody+hens
If she's ill, there might be other symptoms. How old is she, please? Are you seeing conjunctivitis, nasal discharge, sneezing, coughing, increased respiratory rate, regurgitation/vomiting, diarrhea, pale comb/wattles, or lameness?
After reviewing those sites, what do you think is going on with her?