You should keep her in a seperate area for incubation.
Is she very high on the pecking order? If she's low, other hens might try to kill the chicks, but if she's high on the pecking order she will usually be able to defend the chicks fine.
She should be fed non medicated chick food/all purpose flock feed during incubation, and can feed the same thing to the chicks (we don't feed medicated and our chicks turn out alright

) or feed medicated. The hens will usually scratch at the food and teach the chicks to eat.
You should offer a BIG bowl of water (3-4" high) for the hen, and a chick waterer for the chicks (the high water is so the chicks can't drown in it)
Just so ya know, some moms are notorious for ditching broodyness after the chicks hatch, so keep on eye on her behavior for the first few hours after hatching.
If you want to do a double broody to prevent this (we had a cochin who would ALWAYS ditch the chicks after hatching, but this time a Serema went broody too and she's now a loving mom) you can leave her in the general population for up to 2 weeks (she shouldn't be broody for longer then 6 weeks since it causes stress on the body, but some will stay broody until the end of time) and usually that's long enough to get another girl to go.
You should provide some sort of box (dog kennel, shipping box, etc) that will keep the nest dry and cool. If she doesn't get off the nest daily you should kick her off so that she won't poop on the eggs, drink, eat, etc.
clean out the nest if it gets dirty.
You'll be amazed how advanced broody chicks are
ETA;;
Even if she's low on the pecking order, some moms will prove themselves and kill protecting their young (our 2 banties lunge for the throat of anything that might hurt their babies, lol