I would just leave her where she wants to nest! She knows more about being a chicken than you or I ever will. Let her do it the way she wants.
I agree with AArt, let her go out and eat with the flock. It is good for them to be with the flock and establish a higher pecking order. Mine are nearly as high as the rooster. They are crabby and the rest of the flock will give her wide berth. This is when she will dust bath too, and that keeps parasites down. Gives her a bit of exercise, better for her body, and this is how nature intended it. By leaving her in the nest that she likes, she is more apt to return to that nest.
Every two or three days, I go down, using a towel, carefully lift her out of the nest. That is when I check for any stray eggs. As stated, when out for her walk, often times layers will sneak in and add to the clutch. I use a magic marker, as a pencil has worn off for me. My broody's have never stayed with the nest more that 12-18 hours. Then she has gotten down off the nest, clucked to her chicks to make the leap, and creates a clean fresh nest on the floor, where they will sleep in for several weeks. She will introduce them to the flock, and her is where her pecking order is so important, the layers will give her and the chicks a wide berth.
The chicks grow up in the flock. It is the best way to do this, good luck!
ps, if she does get on the wrong nest, and I have had it happened so long that the eggs were cold, but I came to this website in a panic, and was told "just move her back" and the chicks hatched right on time!
Mrs K