She and one of my golden comets are also singing this mournful song in the morning. I understand that this is a kind of pre-egg song. They made the same sound when they were out of feed, LOL. I haven't checked to see if they are doing the squatting thing. I'll have to check that tomorrow.
BTW, my leghorns are about 16 weeks and the comets 15 weeks. I chose those breeds because I read that they were prolific egg layers and early layers as well.
I'm impatiently waiting on my girls too! They are 17-18 week old white leghorns. Out of the 5 of them, 3 have large combs and wattles. I haven't heard any songs. I may put a rock or something to help them whenever they are ready. I checked their pelvic bones today and I can almost fit 2 fingers between them. Here they are.