Until the hen weans it. It is possible the chick will be allowed to mingle with the flock after it is weaned but it is also possible the chick will be banned from mingling the flock until it reaches a certain maturity level. Sometimes the hen remains as best buddy to her chick until it matures or after. You can read a lot of different stories on this forum. Some are positive and some are really sad.
Agreed. But what this often looks like is that the chicks can stay in the general vicinity of the flock without being attacked but if they invade the personal space of an adult they might get attacked. That's why I suggest avoiding single chicks if you can. That way if they are ostracized by the flock they still have a buddy to hang with.
The way I determine that is where does she go at night. If she spends two consecutive nights on the nest I consider her broody enough to give her eggs. If she does not spend two consecutive nights on the nest she does not get eggs.
A tiny Sebright can probably comfortably cover three and possibly four regular sized eggs. You never know how many will hatch or what sex they will be. I'd suggest at least three eggs.
Some hens of certain breeds seldom go broody. Other breeds tend to go broody a lot. This does not mean that a Rhode Island Red or Leghorn will never go broody. Most will not but occasionally one will. This does not mean that every Silkie or Orpington will go broody. Many will but some don't.
Some Rhode Island Reds or Leghorns make great Mamas, most do but some don't. Some Orpington or Silkies make horrible Mamas but most are great. If that Sebright is truly broody and you want her to hatch and raise chicks I'd give her the opportunity. Will it work out? With living animals you don't know how it will turn out.
If you let her incubate and hatch with the flock I suggest you collect all the eggs you want her to hatch and mark them. I use a black Sharpie and draw a couple of circles around the egg so I can tell at a glance which eggs belong. Start all of the eggs under her at the same time to avoid a staggered hatch. Then every day after the other hens have laid check under her and remove any that do not belong. You do not want the number of eggs to build up to the point she cannot cover them all. I've had broody hens leave the nest twice a day for over an hour each time to eat, drink, and poop. I've had hens leave once a day for 15 minutes. I've had hens that I never saw off of the nest at all but I know they were coming off because they never pooped in the nest.
Some people isolate a broody, lock her up so she cannot get out and no other chicken can get to her nest until the eggs hatch. Provide food, water, and clean the poop out as required.
Good luck, however you decide.
getting eggs now to put under her. We shall see!!
