The reason the shadow is gray is because light is bouncing off the other surfaces in the environment. The shadowed area isn’t receiving direct light, but it is receiving reflected indirect light.

(Autistic person here, working on expressing my emotions too) You could try a feelings wheel. There are a few different designs that work on different principles, but the general idea is that they show the relationships between different emotions. I attached a few here so you can see which one works for her best.