you can try what has worked for me on two occasions. and failed on 2..so not sure it's a winner of an idea. I bought two rubbermaid containers from one of the local big box stores.
They weren't expensive only about 4 dollars each I think. I cut a hole in the end of each one and moved the boody in at night. And I turned the opening away from where the other hens could see the boody, so they'd not try to lay in on her.
The other hens will lay in on the broody she'll use that time to get off, dust feed, drink and just strutt around, and when she returns, if the other hen or another is still laying ,she'll go to another nest and just sit on what ever eggs she can find. The other layers, leave and the eggs get cold..
You need to give the boody's access to leave the nest when ever they want to. As they will leave to cool the eggs.

Another thing you might consider if it's not too much work is to take the plastic container out into the yard in the day time and return it to the coop at night. Which might help keep the other hens from running them off, them not being used to laying out of the coop.

The two times this didn't work, it didn't because the hen's found the containers and began to lay in on the broody, but she returned and it was easy to lift the lid to get the fresh eggs from under her. All four times the broody hatched her babes in the containers. I think it might work also because the hen doesn't get confused as to which nest is hers,she'll return to the plastic box on the coop floor and to her nest.
just my ideas, hope it gives you some idea. Chickens, expecially those that want to have families are a lot of work....

Simpleme, I am beginning to realize just how much work a broody is! I was thinking I could make two nest out of milk crates but I did not know that I could put them out in the yard during the day. I have a separate outside for the broodies but inside was my problem. If they cooperate, I could put them out in the morning and in at night and they could get up and eat and drink all they want during the day. I think I will try this! Thanks.

They need shade too.I have a separate broody cage on the north side of our garage but I already had a hen in it so left one in the chicken house.She got too hot where the sun shined in!I got no chicks.Either the eggs were rotten or the chicks were dead(I'm not sure it wasn't the hen!)Anyway it does make a difference .Posy Pet

I use very inexpensive hooded litter boxes for nesting boxes. The chickens love them and they are easy to carry to a new location (handle on the top) and very easy to clean. My hens have learned to lay their eggs in them no matter where they are moved. A broody goose took up space in the corner of their coop so I just moved the litter boxes and sectioned off that area of the coop temporarily with a sheet of plywood. I made another small coop, 2'X4', off the back of my shed with doors on each end. I just move the broody in there, litter box and all, when she goes broody, and close the doors. She's safe from the other chickens, predators and her chicks are, too. I used the very small square wire mesh. It comes in handy anytime I want to seperate any of the fowl, like the mean old ganders when I'm cleaning. It wasn't expensive at all to build and works great.

Critterkeeper, do you think I could move my broodies off their nest and into one of these boxes successfully? Maybe at night?

As critterkeeper said, it doesn't take much to build a small enclosure for your broodie hen, and they do need to be apart from the flock.

Moving them?......well, that's anybody's guess. I try to move them as soon as possible after they go broodie. Usually they stroll around a little and then get right back on the nest. I've had some get off and stay off though. No rhyme or reason to what she might do.

In your case I think it's worth a try. Once you have a seperate area for them, broodies are actually NOT a lot of work for you. It sure is easier than buying peeps and pampering them in the garage until they get big. The momma hen will do all the work for you.