If she's going to go broody, she'll go broody with or without eggs. If she's not going to go broody, she'll do that too, with or without eggs. Weirdly enough, the presence of eggs isn't the end-all-be-all of broodiness. Again, it's a hormone cycle, and neither you nor she can make it start. But some people do leave golf balls in the nest as encouragement. I would never leave eggs, because it can take some hens as much as 2 or 3 weeks to go fully broody once they start actually clucking (which is not the usual sound that chickens make, btw), and by that time, the eggs could be pretty darn nasty. I suggest golf balls. If and when she stays on the nest overnight (assuming she normally roosts), then you put the real thing under her. Only then. Otherwise, trust me, you'll waste a lot of eggs. Good luck, though.
