It sounds as if Henny Penny is committed to setting these eggs until they hatch. She should know what to do, how long she can leave the nest to take her breaks to eat, drink & poop, how often to turn the eggs, etc. All you need do is provide food & water, but you don't have to coax her off the nest or bring food to her in the nest.
You might want to sprinkle a little 5% Sevin dust around the nest box if fire ants are a problem there.
She should accept the chicks as hers, I don't think they care what color they are, as long as they hatch out under them then they think they're their own. Most of my broody hens end up hatching out other hens' eggs, by the time I notice they're broody I've collected all their own eggs days ago. I have a mixed flock & just pick out the eggs from the birds I want to make more of.
It usually takes most of the day for all the chicks to hatch out, the hen will probably stay on the nest all that first day with the chicks. The next day is when she'll probably want to take them for their first outing.
It's a delightful experience to watch a mama hen tending her chicks. I keep my chicken families separated primarily so they can eat the chick starter themselves. I give them unmedicated chick starter, it's all right for the mama hen to eat it too, and the chicks usually pick up immunity to the cocci by being around the mama's poop. Chicks shouldn't eat layer feed, and if I don't keep them separate, the other hens will eat up the chick food, they love it like candy. And, perversely, the chicks seem attracted to eating the layer feed when they can get to it.
I wish you & Henny Penny great success on the hatch! I just set a third broody hen of my own tonight, a tiny little bantam we call Finch, putting 4 full-sized eggs under her. It's going to be funny to see her with 4 big chicks who will grow bigger than their adopted Mom in just a few weeks.