I have Black, Wheaten, Silver, and Lavender LF Ameraucanas. They are all 27 weeks old. The Black and the Wheaten are laying nicely. I got my first egg from a Black LF at 21 weeks old. My Silver and Lavender hens have not yet begun to lay as far as I can tell because I never see them in the nest, and I would be getting more eggs than I am if they were laying too. I also have four siver bantams hens of the same age, and they are all laying.
My Silver hens are smaller than my Black and Wheaten hens. My Lavender chickens are even smaller, but I know that they are about 3/4 LF and 1/4 bantam.