How cold does it actually get there? It's likely they will not need the heater. I would not recommend a heater in that coop - it's much too small and the chickens wouldn't be able to get out of the heat if they wanted to. They may also not acclimate well to the cold with a heater on them all...
Most of the time if I am in a bad mood it's because I'm hungry or thirsty. If that's not the problem, hanging out on BYC, watching videos, or taking a nap usually solves it.
Any signs of respiratory illness? Some viral and bacterial infections can contribute to reproductive issues.
I'd be concerned the chickens might get too much calcium if they are forced to drink water with calcium powder in it. I don't know, though.
She is an Ameraucana-type Easter Egger (Americana)...unless another mix-up happened! I don't think the Olive Eggers from Hoover's look like this, but I could be wrong.