One of my 5 had a mini-molt at 7 months old. And her eggs were really nice & big when she started laying again. Their first BIG molt is usually around 18 months old or so. That's when they lose all their feathers. But any BIG stress can also trigger a molt. And any stress has the potential to stop egg-laying, for a time, while the hen re-adjusts to the "new situation".
Yours may be taking a break, for some reason. Have you had a predator attack recently? Change of location of the coop, etc.? New additions to the flock? Noisy construction nearby?
I have a barely 1 year old hen that was very good layer throughout all the winter. Then she suddenly stopped mid-March and became an irregular layer ever since. I think her shell gland has been undergoing some maintenance. Give yours a little more protein, in the form of fish scraps or a little bit of dry cat food. And give her some time. If she's looking healthy, it may just be time that she needs.