My Chickens Aren't Laying - Help, Please!

I have some lavender Araucana hens which aren't laying. I purchased them about two weeks ago, so they should be settled in by now, and the guy I bought them from says they're about 18 months old. I can't think why they're not laying for me yet. Any ideas?

This is the clearest pic I have... they all look much like this one. Sorry the pic's not so great - they're not tame and I can't get them to stay still!

I know the man I bought them from sold their parents at around the same time - it's possible that I was told the age of the parents rather than of the pullets.

My mum says they don't look 18 months and I agree - but I've never worked with Araucanas before, and they feel pretty sturdy when I manage to pick one up.

Or it could just be that it's been raining all week, but it's been nice the past two days though.

Okay, so it turns out they're only about 15 or 16 weeks, and the guy had got them mixed up in his head with their parents.

To be honest, I had guessed them to about about 3 or 4 months, but I'm rather unfamiliar with Araucanas so when he said they were older, I started freeking out and thinking, "Wait! Maybe I'm wrong! I don't know anything about this breed other than the colour of their eggs! Maybe there's something wrong with them! Maybe I'm just rubbish at judging chicken ages! Are they ever going to lay?"

Sigh. All's well that ends well, I guess, and I suppose I can look forwards to eggs in about two months.