What you allowed to happen is called a staggered hatch. Its Not a good thing. It happens when a hen is setting on some eggs and other hens keep laying in her nest. The way to control that is to make sure you collect the eggs in EVERY nest daily---no matter if a hen is on that nest or not---still collect the eggs. If you want to set a Broody hen "You" should collect fresh eggs(not some that's she has been setting on for a day or two) mark these eggs and place ALL of them under her at the same time. Then every day you look under her and remove any un-marked eggs that have been added----Then All Her eggs will hatch around the same time---usually with in 24 hrs of each other. Then she does not have to Stress over making a decision to stay with the un-hatched eggs or take care of her already hatched chicks.
I always Move All my broody hens to private hatching pens from the beginning then I set her, I do not have to mark the eggs or look under her daily. She is not bothered by other chickens---no getting in her nest, etc, etc. I have set around 150 broodies in the last 3 years, All hatched their eggs within a day of each other---No problems----This is the best way to go in my opinion. Good Luck!