newbie more egg laying ?

one of my buffs just started laying this past weekend atleast thats the 1st one i found. it was right where it was supposed to be in the nest box. i put golf balls in the nests and rotate them around. she layed on sat and sun, but not mon, and today i had another egg. i usually let them free range all day but have been holding them in the coop/run lately until later in the day. my ? is this is it normal at this stage approx 25 weeks to laylike this and also could it be that keeping them in instead of free ranging all day is causing this. also they have a few spots in the yard they hang out in all the time i check them regularly and find no eggs there or anywhere else in the yard, would that hen if free ranging go back to the coop alone and lay there or would she just do it out in the yard somewhere, near the others. thanks for any help