Mark the eggs you want her to have and check at the end of the day for any new eggs. I just make two circles on the egg with a Sharpie, one circle the long way and one the short so I can tell at a glance which eggs belong.
As long as you remove them daily, you can still use them. Sometimes another hen will lay in that nest, if not with a broody them while the broody is out for her daily constitutional. Believe it or not, some broodies have moved eggs from other nests to theirs, even if the nests are elevated.
All eggs are marked and nesting boxes have separators so no way to move from one to the other without breaking them... I checked this morning and all 9 are the only ones in the nest
