Different hens are different sizes and eggs can vary in size. A tiny bantam may have trouble covering 4 regular sized eggs. Who knows how many bantam eggs a large hen can cover. I want my hens to be able to comfortably cover all the eggs plus two more in case another hen lays an egg with her.
I typically give my broody hens 12 eggs the size that they lay in good weather. In colder weather I reduce that so the hen can cover all of her chicks as they grow, usually 8 eggs. I had one hen that had trouble covering a dozen so I reduced that to 10 eggs. I have gone as high as 15 eggs. I once had a hen hide a nest and bring off 18 chicks. I never found her nest so I don't know how many eggs she had. I'm going through all this as it sounds like you want to go all broody hens and this might help you on how many eggs.
Some of my broody hens hatch 100% of the eggs but most don't for various reasons. I've had broody hens complete the hatch and come off within 24 hours of the first one pipping. I've had broody hatches stretch into the third day before bringing them off of the nest after the first one hatching. I let my broodies handle all of that. They know more about being a chicken than I ever will.
The chicks absorb the yolk before hatch and can typically go more than 72 hours without eating and drinking while waiting on the later chicks to hatch. When they get hungry or thirsty they peep at the hen to tell her so she leads them off of the nest for food and water. It sounds like that may have happened to yours. I find it interesting that you were able to get her back on the nest and to accept the eggs. I don't see that but I don't try to get her back on the nest. Since the chicks have been fed and watered she may be able to finish hatching at least another chick. Good luck!