1. You should either move her, or fence her nest in. Also, 16 eggs is way too many for one chicken. You need to reduce the number to something she can comfortably cover all at one time. She will rotate the eggs around, and they will all spend too much time on the edges and die.
2. It depends on whether she has actually started incubating or not. If she was off the nest waiting for you, I wonder if she has actually seriously started. I would candle. If you see some development, leave a reasonable number under her and check again in a few days for movement.
ETA: At the moment I have 7 broodies, and I don't want any more chicks this year......augggh!