Yeah they should be okay with their mom hopefully she is a good mom and takes care of them. If not you might have to raise them yourself until they are old enough to be introduced back into the fold. Or unless you have a hen that doesnt have chicks, she might even take them in and raise them as her own. Some hens will do that.
Now if you have to raise them it will be just fine... But when they get bigger you'll have to keep them seperated from the other flock members untill they get use to them there might be some squabbling but they should be able to fend for themselves
the chicks well if it was me personally id wait a day or two, or until she comes out with them maybe a few days?? but you can hold them when they are out. I dont know if you wanna hold them after they hatch maybe a hour later. but make sure momma doesnt have a problem with you holding them lol....
Like I said you can wait when she brings them out and then hold them.. So that they get use to you..
I remember when my hen a RhodeIsland Red had her chickies and they just hatched she would let me hold them course she was use to me ever since she was a chick herself, however when my mom and dad tried to hold them she would peck at them lol.. Not until she brought them outside would she let anyone hold them
if you want.. you can always use some red light heat lamps and put them in the coop.. that will keep them warm too.. Or you can use hay.. thats what ive been using at night for them. and then put hay on the sides of the dog house for my chickens..