I texted my friend that raises them and she said 5 months was about the time for hers.
If you still have them on starter/grower, I'd keep it that way until they do lay, then switch to layer as layer feed has way more calcium and usually less protein than their grower feed does. It's getting that time of year for our chickens to slow down or stop or go into a molt even, but seems odd that by now yours wouldn't have at least laid a few before taking a winter break, but maybe they sensed it.
A year old and not laying is very rare for a chicken, but it does happen sometimes a hen is infertile. It can also be the effect of a disease or a problem with parasites like a mite infestation (check and treat if you notice them).
In general this is the time of the year for many breeds in the northern hemisphere not to start laying because of the daylength and colder temps. They start to lay in February or March.