The broody I have has hatched eggs before (in July). She is the best broody anyone could hope for. She takes great care of the eggs and chicks. She is extremely protective, but not overly aggressive. I have no doubts that she is going to go back to her nest when I take her off. I had another broody that was not a good mom and I had to watch her all the time. One time the good broody stole all the chicks from the bad broody and I had to separate them all. LOL Each case is different so you have to do what works for you. In my flock I have one older hen that can get rather pushy. She is the only one that will peck at the broody until she gets off the nest. Pushy hen then lays her egg in the nest while the broody stands outside the box and waits. At least the eggs are being covered by someone when the broody is kicked off. I candled the eggs on Saturday and they are all developing normally to date.
She sounds like she k owns what she is doing! My hen is an excellent setter so far, but we will have to see if she is a good momma. Fingers crossed! How long till yours hatch?