So you do have a broody hen. I'd have left the eggs under her instead of putting in a homemade incubator. You'd have had better success and the hen would brood the chicks for you too. Win, win. Now you have to break the broody hen in a cage or other method. You don't want her on a nest for three weeks if she's not hatching the eggs.
Since you're at 7 days I'd wait few more days and candle again. It will be very obvious which are developing day 10. Toss the rest. You've already determined the start of incubation. Tuesday plus two days is Sunday was the start of incubation. If you went back into the coop Thursday and pulled fresh laid eggs then you have a very staggered hatch. It won't go well. If the eggs given to you Tuesday were not put in an incubator that day then they likely died already. Did you mark to differentiate the two taking of eggs?