My girl is a 4 month & 1 week old barred Cochin Bantam. She is one of 16 hens.(3 roosters present) She is coo-coo-coo-coo-cooing repeatedly, her vent is clean and nice yellow color. These birds free range all day and head to the coop at night. Her "cooing event" began early this evening. Is she old enough to begin laying?