8 Month old Australorp hen not laying or roosting

[golddeer]

We bought an 8 month old Australorp hen on craigslist about a month ago. She's super friendly and we love her but there are two problems. First, she doesn't roost at night. She insists on sleeping in the coop nesting box. Second, she hasn't laid one egg yet! We live in San Diego CA so I don't think winter weather is the problem. Any comments on how to get her to roost at night? We have three other (younger) chickens who roost just fine each night in the coop. And what about egg laying? Thanks for your comments!