So, here's the cover discussion I mentioned (This description is very long and detailed—sorry— because I have a particular scene in mind and want all the clothes and things to match up with the description in the story. You don't have to put all the details in. Just do what you think would work):
So, the scene I'm thinking of has Maruca, Dex, and Biana in it. They're standing kind of close, with Maruca holding her arms up, summoning a force field around them. The force field is half cut off by the edge of the scene because there are a few other people also in it that I don't want in the cover image. The scene is a human soccer field at night, probably a moon also. The background can be pretty simple. Light is illuminating the three people, both from the force field and from a flashlight (okay, it's not actually a flashlight, but that's the best way to describe it) being held by one of the people in the force field but not in the image.
For the different people's looks:
I think I like how Maruca's hair was depicted on the "Stellarlune" cover, but I have different clothes in mind for her—a light blue tunic with pockets and dark gray pants with tiny butterflies around the ankles. Maybe some simple jewelry or something. They're trying to look like humans, so nothing too elaborate.
For Biana—this scene takes place after Nightfall, so she has her scars. I really like how you drew them in your KotLC art book. She's wearing a golden yellow tunic and black pants. No makeup. If you want to give her jewelry, also simple, could-pass-for-human style.
Dex is wearing a dark green tunic with buttons and pockets, and long grayish blue pants also with pockets. The pockets noticeably have things in them.
I don't care about anyone's shoes, just make them wearing whatever shoes you think would work.
There is no urgency, take as long as you need. If you feel like it's not working out, you can tell me you don't want to make the cover after all.