Giving her more fertile eggs is a big mistake. She is already incubating eggs that are developing so by the time they hatch she will most likely get off the others and they will die. I would take them out right away. If you can't tell which ones are the newer ones then candle them. Give the newer ones to another broody or use an incubator. You could even eat them if given to her the last 24 hours.
I would keep the door open until day 18. Great pictures.
I would keep the door open until day 18. Great pictures.