The Princess of Lakishea

It's good that you've said this isn't entirely original, but you've not been clear enough. Your description should state very clearly that this was based off someone else's work, credit the original artist by name and provide a link to the original work, so that there is no confusion. It's perfectly fine to find a picture online and think it would make a good cover for your story or use it to practice your skills, but I'm sure the artist would feel upset that appropriate credit isn't given here.