My hens quit laying as many eggs in the fall/winter. Is something wrong with them?
Likely your hens are normal. As the days get shorter the egg production of you hens may drop off considerably. Chickens need about 12 hours in the afternoon and nighttime to produce an egg and its surrounding shell that will be laid the next morning.
As the day length decreases so does the number of eggs that can be produced. You can counteract this natural cycle by artificially increasing the day length. Set a 40 watt bulb on a timer to come on earlier in the morning so the hens get a total of 16 hours of light a day.