If you want to tempt them, get some plastic Easter eggs (color unimportant) and put them in a cluster in the nest you'd like a brooding hen to use. I put rocks inside for weight and taped them shut when I made my dummy eggs. If one takes the bait and sits all day and night, swap the fakes for hatching eggs. Be sure to mark your hatching eggs as chickens may lay in the broody hen's nest while she's eating/drinking.
Also, the PP who said that it's hormonal and not all will go broody is absolutely correct. I have a hen that will sit all night on any egg left at dusk and she's a Marans from a breeder. You'd think she'd go broody but she never has. She does a fine job keeping any winter afternoon eggs from freezing for me, though! I also have one that will gather eggs from the different boxes and put them together into one nest. You'd think she'd sit on them after all that trouble but nope! She's an EE, never has been broody.