She's as if being separated anyway. Mine lose their place in the pecking order if setting more than a month even though they are right there in the coop with the rest of the flock. She's zoned out and doesn't have a thing to do with any of the others. If you wait till after dark and quietly go in and slip a few chicks under her, so long as the chicks are a week or less old, she should accept them as hers just fine. But do watch her a minute after you do it to be sure she just settles right down, and take a look in the morning to be sure all is fine. She should continue to set a day or two before getting up.
You'd want to block her off from the rest at this point though so the babies can get up and get food. When a day old, they can go w/out but not after a few days old. She'll continue setting a couple days to give any eggs that haven't hatched yet a chance to hatch. We know that no more will but she doesn't. Her hormones won't let her get up for a day or so.