Some chickens have large combs, some have small combs. Some hens have almost no comb. That's controlled by genetics. Size of the comb is not important at all. Black sex links are not a breed but are some kind of cross. As they are not a breed there are no breed standards for combs. They can be huge or tiny.
Before they start to lay, most pullets will have a bright red comb and bright red wattles, that is the sign you should be looking for, not comb size.
Hatcheries say a lot of things. People that post on here say a lot of things, including me. One thing I regularly say is that each chicken is an individual. Some of the same breed or even full sisters might start laying fairly young, others may wait months before they start to lay. If you have enough for averages to mean anything you can kind of go by what a large flock might average, but with only 1 of each you don't have enough for averages to mean anything.
There are other factors involved in when they start. Whether the days are getting longer or shorter can have an effect. Length of day can have an effect, these are different things. I've had pullets start laying the first week of December when the days were getting shorter and are about as short as they will get but these did start. I've had some wait until days got longer to start. In Calgary, you are probably experiencing some cold weather. Extreme heat or cold can affect how much they lay, let alone when they start. There are other factors. To me the big one is that each is an individual and will lay when they lay.
I once waited nine months for my three Ameraucana to lay the first blue egg. The breeder I got then from said hers tend to lay their first egg around five to six months. My other pullets tend to lay their first egg around five to six months. The pullets I hatched from those blue eggs tended to lay their first eggs at five to six months. I have no idea why those three took so long to get started. You may be feeling frustrated but trust me, I was much more frustrated.
So hang in there, you will get eggs. I have no idea when.