A couple of times, I just had to go with it and slip the right eggs under her.
I was excited to see that, with very little help from me, she had a little peeper (the fuzzy gray spot at the bottom of the picture) last Saturday evening and she was clucking contentedly.
She started out with six eggs, then three, then the final total was about a dozen. After hatching three, she abandoned the nest. So we took her out, held her upside down by her feet and dusted her with Sevin 5% dust in case she had gotten lice or mites while sitting for so long. Then we moved her and her babes into a cage and put her in a stall in the barn, hoping to keep the chicks safe from predators.
They stayed in the barn for a week. To minimize trauma, I waited until she had bedded down in the cage nest for the night, closed up the door and covered the cage with a sheet, then moved them into the guinea coop as a transition to the outside.
They've been happily scratching away in there all day. When I think they're big enough, I'll let them out with the rest of the chickens. Hopefully, she can keep them alive without to much help from me.