Humanoids that look like elves run the Pet Trades and Premium Shop. Their skin is an aqua color, which makes me think they're some sort of water spirit, like a nymph or aquatic elf. Though their hair is fiery red, which isn't very waterlike at all, and their eyes appear to have black scleras and red pupils.

According to Europan lore, Europa was settled by humans and its animals, the beasts, were created by genetic manipulation. So where did these elves come from? Are they native Europans who now work alongside the humans? Were they also created by the humans by splicing human genes with some other animal?

It's clear at this point that humans are now the dominating empire on Europa, but we've learned nothing about these mysterious turquoise elves. They just run the shops.

Our shopkeeper is a genetically modified human.  She is not an elf from the fantasy worlds like D&D, Middle-earth and others. Those elves have extended lifespan and magic abilities while the modifications of this turquoise lady are purely cosmetic

Pointy ears are quite rare, but they are possible even today with the help of plastic surgery or may appear natually due to genetic disorders. And though we don't  recolor the skin of human beings into green, this is not something extraordinary. Melanin isn't the only skin pigment, and hemoglobin isn't the only protein that transfers oxygen.

Probably the most popular modification of that type is related to GFP gene found in jellyfish. It is responsible for production of a fluorescent protein which glows green in darkness. This gene was implanted to different kinds of animals including mammals. The result was fabulous:

Genetically modified people of Europa have all types of utilitary and cosmetic genetic modifications obtained the same way that GloFish and Glow Cats got their GFP gene. 

@Angel

Thank you for clarifying. Though Europa's beasts are genetically modified, I wasn't sure if humans were the same, so I thought that perhaps she was a supernatural being.