Well, here's what you need to do now. Tonight, you need to go out with flash light and candle. Make sure it is a very strong flashlight. Candle all the eggs. Anything with veins, put back under her, and thing with out, take out. Any thing over 3 days under her should have veining by now. THEN count 18 days from today for your hatching. OR you could leave everything under her, and hope she'll sit on them all till they are done if it hasn't been added eggs over more than a few days. Still start your count on days from the day you first noticed her sitting on the eggs. Usually though, after the first chick hatches, the moms usually start showing them the food with in 2-3 days, have a habit of then staying right by the food and water, OUT of the nest. At least all of mine have. They vacate the nest with in a few days of hatching. The only hen I have had that ever continued to use the actual nest was a silkie hen. All the rest just nested on the floor till the babies were able to start roosting.