Just put her in a small dog crate at night. However, this can be a sign that you have space issues. Can you take some measurements and pictures of your coop?
Some birds can take a little crowding, and some can't tolerate it at all.
I see you have just joined us, welcome. I also note that you seem to have 6 birds, I am wondering if you have one of those darling pre-fab house that claim they will hold 6 birds? If so, space can be a huge problem. And the crate will just be a temporary fix.
Mrs K