Unfortunately true
The comb is a little on the small side for a male of this age.
Then again, it's big for a female of this age.
If I assume this bird has been bred for high egg production, which usually goes with a large comb for the age/sex of the bird, then you might have a female. This is especially likely if the bird is a little older than you were told, and has been growing up during the long days of summer (which can cause a chicken to mature earlier than it otherwise would.)
On the other hand, if the bird is a little younger than you were told, and is a slow-maturing type, then that exact same comb could easily belong to a male.
My gut feeling is that the bird is female, but I don't trust that unless I can point to specific reasons to back it up. In this case, obviously I can come up with a list of reasons either way.
If there are others of the same kind to look at, you might be able to tell more about the combs. If they are supposed to be sexed females, and they all have similar sizes of combs, that probably is the correct comb size for females of that age for that breed or mix. But if the others all have much smaller combs, then yours is probably male. It does look old enough that male vs. female should be pretty obvious if you get a chance to see both sexes.