Lisa is five years old and best friends with Taylor Grace. She is older than Taylor, but they act like it is the other way around.
She is at Taylor's house when Luke and Dawn show up. The girls quickly flee to Camp Half-Blood.
While at camp, they get bored and decide to wander off. They get lost and have to spend the night in a derelicit park.
The next morning, Lisa is the only witness to the kidnapping of Taylor by Dawn.
As a 5-year-old
Lisa is fairly short at 3'2. She has a thin build, weighing around 46 lbs. She has long, straight almost-black hair and wide pale green eyes. Lisa mostly takes after her father; she has Percy's hair and eyes but Annabeth's facial features. She has Annabeth's tanned skin, too.
As a teenager
Lisa looks relatively the same, though her hair is longer and darker. She is now 5'5 and 130 lbs. Her eyes also darkened of a bit and are more of a seaweed color than just "light green."
Lisa is a bit of a tomboy, but not as much as Taylor. She likes Barbies, My Little Ponies, swimming, and animals. She is very artistic; she wants to be a painter when she grows up. She is a friendly and outgoing girl, always skipping around talking to adults, other kids, and anyone else who will listen. Lisa isn't as strong as her parents, though, and can be pushed around fairly easily (especially by Taylor, though this is partly due to their close relationship). She is very neat and hates to get dirty. She likes reading books with her maternal grandmother, Athena, who visits her regularly. Like her mother, Lisa is smart and hates spiders. Her favorite color is red. As a little girl, Lisa wears things like blue Barbie and Ken t-shirts. As a teen, she's very tomboyish, but likes to throw in girly touches.
- Annabeth Jackson (Mother)
- Percy Jackson (Father)
- Athena, Sally Jackson (Grandmothers)
- Poseidon, Frederick Chase (Grandfathers)
- Paul Blofis (Step-grandfather)
- Mrs. Chase (Step-grandmother)
- Tyson (Half-uncle)
- Lisa is possibly named after Lisa Simpson.
- In the first drafts of Whispers in the Dark, Percy and Annabeth did have a daughter about Taylor's age, but her name was Nikki (the name that was later given to Taylor's younger sister). She had light brown hair and hazel-blue eyes, like Percy's mother. Her personality was quite different from Lisa's as well; while Lisa's personality is very close to her mother's (smart, tomboyish, bookworm, neat, and maybe a bit fiery), Nikki was quiet, shy, passive, and insecure.
- How Lisa was created: Sparrowsong made Percy and Annabeth in The Sims 3, a life simulation game for PC. They had two children, one of whom was Lisa. Sparrowsong liked Lisa so much that she decided to include her in Whispers in the Dark. In The Sims 3, Lisa's Traits are Neat, Artistic, Friendly, Great Kisser, and Good. Currently in The Sims 3, Lisa is married and has a daughter named Athena. Athena has the Brave and Virtuoso traits.