Hen stopped laying from stress? not sure

[click cluck]

We have a 7month old hen named Abby (my profile pic is her as a chick), she is one of our best layers and all of a sudden she's stopped! Its been about 3 weeks now and still no eggs from her. One of our RIR has pecked a bunch of Abby's cheek feathers out on one side, the RIR has never done that before so I'm hoping its just hormones that will pass, I haven't seen her peck anyone in a week, could it be stress from that? Is there something I should do to help her start laying again? Can this be a big issue to her health wise?
Any advice or experience is appreciated! thanks!

click cluck
p.s. She stopped the day after we had a really bad thunderstorm and had to rescue the chickens from under the coop so they wouldn't drown (it was that bad!) And also the last few weeks we have had packs of coyotes screaming around behind our back yard at like 3am, that creeps me out! Its probably stress I would say.

 

[ChickenCanoe]

Stress can stop ovulation. It may also be related to the time of year. Decreasing day length can stop ovulation.
If all your birds are the same age (under a year), you can add light to the coop to increase day length to over 12-14 hours and that may kick start them.
Feather picking is sometimes related to space and sometimes a need for more protein.