Ok...where's deerman to answer this one?
I'll try to hit it up best I can for now. I also have silkies and raise a few pea's every year too. Incubation with them is very fussy compared to chickens. Best to have a broody sit on them for you and them move them to the hatcher for the last few days. Humidity has to be just perfect and I've only had luck in 1 of the old redwood incubators. If you leave them with the mother peahen, they will hatch well but I've found that all the chicks slowly disapear one by one. I've had broody silkies hatch a few, but they have problems keeping the babies alive too.
Peachicks are essentially dumb. They really don't know how to eat on their own at first it seems. Mealworms or something that moved to get their attention sometimes works. I know the peafowl breeders might say no to this, but I put the peachicks in with my silkie chicks and they learn to eat with them. The peachicks are also too dumb to sit under the heat lamps too it seems like. Brooding them with my silkies helps and they keep them warm. If you can get them past the baby stage, you have done well.
Peachicks are really sensitive to alot of diseases that chickens aren't. Most pea's are raised on wire for that reason. I keep my silkie brooders super clean though and they don't seem to have a problem with them. Worming is a big issue...keep up with regular treatments of Wazine/Ivermectin in the water.
A 3 month old will hardly be in a brooder anymore. By about a month old they are already 6"+ tall and by 3 months they are closer to a foot. They will be flying and perching on stuff by the time they are a month. Last year I raised some in a 10' wide x 30' long x 8' high flight pen. I still lost a few because they tend to fly into things, crash, and sometimes remind me of Wily Coyote. Self destructive....
Best idea is getting started yearlings if possible...