Hi 'TheKindaFarmGal' honestly I can't say other than my son got it around 6 months ago.
He (son) isn't the most "observant" so his response to how big was 'she' etc is oh a bit smaller but that could mean virtually the same size up to being say half as big but pretty safe it wasn't chick sized. I will say that my son's dad was surprised when I told him on Sunday night that it was trying to crow as obviously he had never heard it and he is an early riser who would be outside around that time of day (ie early morning).
At dad's place was definitely the smallest chicken which makes me wonder if it decided that being only chicken here (at time) that it would be the dominant one and start acting like a boy.
You definitely have a girl. She could be just a hen that crows sporadically, or singing the "egg song". And she is a Polish, maybe a mix.