If you know that she’ll start laying soon then why make a poll? /:
From my experience, red combs do not indicate imminent laying. My OE were bright red, like cockerels, for two months before they started laying. Whilst red combs do usually mean they’ll start laying soon, much like squatting, it’s also just a sign of sexual maturity, not a sign of eggs for breakfast. Given it’s also getting towards the end of the year, some pullets that haven’t yet started laying may take even longer to begin. So in my opinion, 20-30wks is a good vague age for pullets to begin laying in winter.