It is perfectly natural for heritage hens to go broody. It is in their genes! The heavy breeds are more inclined to do so than the light breeds. Pekin bantams and silkies are renowned for making great sitters and excellent mothers. If you have discovered a broody in your nest box there are two options available to you.
Make use of her broodiness and use her as an incubator. This is done by placing a setting of hatching eggs (fertile) under her so she can incubate them for 21 days. Broody hens on most occasions make excellent mothers and are nature's way of producing the next generation (well that is what they are here for!) and don't forget hens do not lay forever so refreshing your flock every 2 to 3 years is a good idea.
Snap her out of her broody state by removing her from her current comfortable environment. Take her away from the nest box to a separate wire/netting cage with fresh water and feed. Wire netting on all 4 sides is best. The Eglu Go Hutch with 1m Run works a treat as a holding pen if the hen is shut out of the house and kept in the wire run. Do not offer her any ‘creature comforts’ other than some protection from wind and wet weather would be kind. Leave her in the wire cage until she has got over her broodiness then place her back in the laying pen. This can take as long as a week or two.
Here at Appletons we keep many different breeds so as the hens go broody we remove them and place them in a communal pen with no creature comforts. Having new house mates upsets the pecking order and so their minds are taken off being broody and focused more on sorting out who is who in the sin bin! For the best results act quickly within 24 to 48 hours of her going broody to snap her out fast so you can get her back into production quickly. Broody hens are unproductive hens especially if left flitting away endless hours and days sometimes even weeks sitting on no eggs or your fresh eating eggs!