Opa, think I could slip a few 3-4 day olds under her when I recheck the eggs monday? I really think 4 are duds, but I want to give a few more days since she's been kicked out of her nest so many times over the last week...
How long has she been sitting? If the new eggs are more than a day or two from the originals I would advise against it. When the eggs hatch she will either abandon the new eggs or she will stick til they hatch causing undo stress to the hen and possible the first chicks.