How to know when Silver Laced Wyadottes are ready to lay?

[Weeg]

I recently adopted two Silver Laced Wyadottes who had mites from a family member, I then treated them for mites, and I believe they are free of hem and finally ready to enter my flock! I am wondering though, when they will be ready to lay,and how to tell. I don know how old they are, since I adopted them, but recently I had seen more red in there combs. I don't think they are fully matured yet, but am wondering how I will know when he they are, and how much longer you thin it will take, if you have an idea. Thanks here are some pictures!

 

[cherrynberry]

once they start squatting. Looks pretty close!

 

[Weeg]

once they start squatting. Looks pretty close!

Oh good! I have never owned the breed before, so since they don't have super big combs it is hard for me to tell!