Stella Luna is a pre-made townie from Oasis Landing who can be seen wandering around town. She can be made playable by marrying her, asking her to move in.
Although it is not stated in her family tree, she could be the wife of Juniper Luna, and the mother of Maris Luna. Like all pre-made Sims from Oasis Landing, she has the Future Sim hidden trait. She has mastered her Advanced Technology skill and has 4 skill points in Laser Rhythm-a-con.