You can make a hen go broody, by putting her in a small box or something, with air vents of course, whatever you put her in, it has to small enough that she cant move around alot and it HAS TO BE dark. You may have to keep her in there for a few days or even a week. You let her out once a day to eat, drink and potty for 15 or so min., then you put her back in. I put fake eggs in with her also.
Ive had some hens go broody in 2 days and some it took almost a week, but it does work.
or you could let some eggs in the nest at all times, removing the older eggs everyday, sometimes this has worked, and it may take a few days also. I mark the eggs that were laid today, I remove them eggs tomorrow and let what was laid in the nest tomorrow, marking them so I know to remove them eggs next and so on.........................or you could let some fake eggs in the nest at all times then you dont have to mess with marking eggs and so on. The fake eggs I use are either wooden or glass...............Good luck..............