My girls (3 BR and 3 RIR) have been in their coop for over two weeks and are doing great. Today I was cleaning their coop and found some poop in their nesting boxes. I know they are not sleeping in them because they have been sleeping on their roost for almost the whole time they've been in the coop; they started roosting after a few days. Anyway, we were gone for a couploe days and when my sister came by to let them out of the coop she saw one or two of them in the nesting boxes. Should I allow them to go into the nesting boxes right now or should I wait until they are closer to egg laying maturity?
Below are pics of the nesting box and my girls.
Below are pics of the nesting box and my girls.

