Hi, you never know what might happen! We bought back a 3 year old ewe who had never been bred last spring. Our sheep (cheviots) only cycle once a year, the first 2 weeks of March (now!) are always very busy lambing time for us! This ewe surprised us with a lamb on August 31! We never forced a weaning, just left the lamb with the ewe all winter. The last time I observed her lamb nursing I think was November or December. Well, she just had another lamb 2 days ago, so she got herself on schedule with the rest of the flock. I think it really depends on the breed, but when the ewes do go into heat, they tend to all go in at the same time!