Lilo is a young girl with long, straight black hair and brown eyes. She is most often seen wearing a muʻumuʻu and sandals, but also wears other warm-weather clothing as well as traditional hula costumes. In Lilo & Stitch 2: Stitch Has a Glitch, her reflection in a mirror is compared to a picture of her young mother, suggesting that they look similar. In the episode "Skip" where an experiment is used to skip time 10 then another 10 years, it is mentioned that older Lilo looks a lot like her sister Nani.
Her spirited and highly eccentric personality, especially in light of her parents' death, has alienated her from her fellow children, yet Lilo makes the perfect best friend for Stitch, an alien experiment whom she adopts as her dog. Lilo attends Hula school and her hobbies include the photography of obese people, talking about creatures from horror/sci-fi movies, and capturing and rehabilitating Jumba's evil genetic experiments. In "Swapper" she meets Victoria, who turns out to have similar personalities to her and she becomes Lilo's only human friend, she also attends Lilo's hula school. In "Spooky", it is revealed that Lilo is afraid of broccoli, clowns, and the scary/haunted house on the hill nearby where she lives. It is also revealed in this episode that Lilo, like her father, plays guitar. While frequently shown to be a strong swimmer like many Hawaiians, Lilo is also a strong free diver, shown when she swam from the stalled x-buggy in sub-mode and carrying Rufus, to Drakken's lair on the bottom of the ocean to rescue Kim Possible and Stitch.
Lilo's parents died in a car accident some time before Lilo & Stitch (it is suggested that rain made road conditions treacherous), and they have not appeared in the series apart from three photographs: one of Lilo, Nani, and their parents having a picnic on the beach, a photograph of Lilo's mother winning the Hula contest at her school's May Day celebration, and a photo of Nani with her parents when she graduated to intermediate Hula.
Lilo's mother is depicted as kind and loving (and perhaps eccentric like her younger daughter), as well as an excellent hula dancer. She would placate her children by holding a family night, singing lullabies, and making up funny constellations. Lilo's father played the ʻukulele and was the one who coined the phrase ʻOhana means family, and family means nobody gets left behind or forgotten. The phrase becomes a sort of family motto for his daughters and their intergalactic adopted clan. Lilo loves and misses her parents very much. She keeps a picture of them under her pillow and initially would not allow Stitch to touch it (rejecting him when his fight with Jumba caused her house and the picture to become damaged). In the episode "Remmy", which takes place on the anniversary of the accident, Lilo is depressed and takes a nap to help deal with her sadness. The picture is used to turn Lilo's nightmares into a dream of the day the photograph was taken, which manages to make her happy again (in this episode however for some strange reason the picture is completely undamaged).
The development of Lilo's ʻohana (extended family) begins with the adoption of Stitch in Lilo & Stitch. Though Lilo technically owns Stitch by Hawaiian state law, the relationship between the two is more like siblings and best friends. By the end of the series, Lilo's extended ʻohana includes Nani, "Uncle" Jumba and "Aunt" Pleakley, David, Cobra Bubbles, the Grand Councilwoman, Victoria, all 627 (627 and 628 were shown dehydrated in the episode of 627, although it could be argued that they still count) of Stitch's "Cousins" and finally "Mertle".
Lilo does not return as a main character in the anime Stitch!. The original version (aired in Japan) leaves a plot hole for why Stitch is not with Lilo anymore, as Stitch is first seen in the first episode wreacking havoc in outer space and is being chased by Jumba and the authorities with no mention of why he was back to his destructive nature or why he left Lilo. For unknown reasons, they wanted to leave this open to the viewers' imagination. However, in the heavily edited English adaption of the anime, it is implied that Stitch is doing this because of emotional trauma, as Jumba tells him, "Just because little girl Lilo, has new boyfriend now and is all washed up with 626 (Stitch) is no reason to act bad", suggesting that the now grown up Lilo has deserted him for a new boyfriend. Despite this, when confronted by Yuna (a Japanese little girl who is the series' equivalent to Lilo) about his family not caring for him, he states "Lilo cares," which implies he still thinks she cares about him. However, Lilo does not appear in any way in the anime, except for Episode 23 of Zutto Saiko no Tomodachi (Season 3), where Lilo, now a fully grown adult with a daughter who looks incredibly like her when she was a child, visits Okinawa in cahoots to reunite with Stitch, where we learn that she still truly loves and cares about him. We also learn the reason why Stitch left her was because she had left for college and she did not visit him on the beach the day she promised him, causing him to believe she had betrayed him. Lilo then explaines to Stitch that the reason why she did not visit him on the day she promised was because Nani became pregnant and she was very busy looking after Nani, by the time she rushed back to visit him he had already left; she discovers this by finding his tiki necklace on the beach, causing her to burst into tears. At the end of the episode just before she boards the plane with her daughter, she and Stitch have a happy reunion, she hugs him soundly, gives him back the tiki necklace which she had kept with her since he left and promises to visit him again soon.