What a cute photo - and what a cute set up! I didn't realize you couldn't lock them in at night - sorry about that. Can you get in there at dusk to pick them up and put them in their coop like KarlaMaria suggested? Do it at dusk when they're falling asleep and they 'should' stay there. The light may attract them to the coop but I've never had to do this so can't really say. A chicken needs light 14 hours/day in order to lay. If you don't have that where you are, then you'll probably want to add the light.
Good luck - what kind of girls do you have?
Good luck - what kind of girls do you have?