The only picture I could see was the one with a single chicken, it looks like a girl to me. A sebright hen.
The wyandottes, when you say you bought them online, are you talking about a hatchery or a private seller, like someone on craigslist.
If it was not a hatchery I would suspect that someone sold you much older chicks than you think.
I have wyandottes the same age and they are just little things still.
My hen that started laying for the first time today is 4-5 times the size of my 9 week old wyandottes.
If you can post pictures of the girls that you think are 9 weeks old it would be helpful.
As far as the other question, as everyone said, roosters do not lay eggs, but hens will crow. I do think you have a female sebright or some kind of mix maybe. Its not a very big picture but thats my guess.