I think you need to collect the eggs. Your hen is not broody and will not hatch them. If she ever starts acting the way brooding has been described here, that's when you leave the eggs in the nest. You are just allowing edible eggs to go bad at this point. Also, eggs left in the nest could get broken by one of the hens and then if they acquire a taste for them, and they will, you'll have a whole new problem on your hands. I'm pretty surprised 2 roosters and 2 hens is working out for you. Usually the roosters fight and the hens get over-mated and lose all their back feathers. Good luck! Hope one of your hens gets broody this year. How old is your bantam? Are these her first eggs?