I think one of my chickens stopped laying?

I don't think my Austrolorp has laid any eggs in a few weeks. She is around the age where she will start molting, and I know they don't lay when they are molting. It looks like she may be losing some feathers, but I'm not sure. How long before they start molting do they stop laying? She appears healthy and unstressed, and they get all the nutrients they need, so I don't think that's the problem. Thanks.