Is RIR ready to lay?

[kmb221]

My RIR, approx. 16 weeks old, was acting weird last night. All the other hens were standing around and she just plopped down on the grass. I went out to her, she didn't get up. Just sat there. Went out at dusk to make sure they were all on the roosts and she was up with the other ones.

Is she getting ready to lay? I'm a newbie and am not sure what signs to look for before laying starts.

I have 1 RIR hen, 1 RIR rooster, 1 Buff orpington, 2 Silver-laced Wyandottes and a Black Autralarps.

 

[Curlita]

I don't know if it has anything to do with laying eggs or not, but that's how my chickens act when they are taking a dust bath or have found a nice sunny hollow.

One sign that they are on their way towards laying is that when you stroke their back, they crouch down and do what I've come to think of as a "come hither Mr. Rooster" dance.