While Patti is very child-like, Liz is more like a teenage girl (worried about makeup, shopping, etc). Despite mostly being the cool-headed and serious of the sisters, she is shown to be extremely afraid of paranormal things, convinced that any ghost she meets is out to eat her (where her paranoia severely irritates the ghosts that are trying to help her). She can also be a little cynical and shallow, and sometimes takes advantage of other people for her own gains, like when she pretends that Tsubaki's cooking is her own to impress a boy she likes. She can be flirtatious and can also be charming to men, mostly in order to decieve them (which is shown when she tricks Giriko alongside Patti).
Both Liz and Patty admire Kid's dignified soul due to the fact that they are from the streets. Unlike Patti, Liz finds the drama brought on by Kid's perfectionist attitude annoying. Also, Patty adores her and thinks that Liz knows everything.
She is the older and more mature of the two sisters. Kid's obsession with symmetry and how he'll sometimes let it control his life sometimes gets on her nerves and she frequently reprimands Kid for this, although she won't hesitate to cheer him up when he is depressed. She also displays some courage and determination whenever her friends are in danger, and tries her best to protect them.
Liz has light caramel-colored brown hair that reaches her mid-back, dark blue eyes, and tanned skin. She has a smaller breast size than her little sister, which annoys her to no end, though she is much taller. Both of the Thompson sisters wear cowgirl outfits: A tight sleeveless red turtleneck belly shirt with a white tie, cowboy hat and black high-heel boots. However, unlike Patti, Liz wears long jeans and also wears two silver bracelets on each wrist. Also there is a subtle difference in their hats. Patti's hat has rounded rims, whilst Liz's hat has rims that slant forward. In the anime, as the series progress, both Thompson sisters wear cropped white jackets over their outfits. Liz's soul has a pink color and has two curved triangles representing her hat.
In her new Spartoi uniform, Liz wears a zip-up top over a blue vest and a white sports jacket over it. She no longer wears her cowboy hat, and her jeans are replaced by a blue pleated skirt.
Out of all the characters, Liz changes the most physically when entering the Book of Eibon. Her appearance is that of a heavily-built man with closely cropped hair and piercings on each ear, wearing a white jacket and dark pants. Despite her threatening appearance, she still displays her squeamishness and cowardice, much to Patti's amusement. Also, she along with Tsubaki remain in their opposite gender form the longest, revealing that they are the most lustful out of the group. However the most lustful of them is Tsubaki, as Liz turns back to normal slightly before Tsubaki.
- Both Liz and Patti collect souls in the magazines of their gun forms.
- Back when she and Patti were on the streets of Brooklyn, it showed Liz smoking and getting high.
- Liz, just like Patti, wears a thong, even on missions. While hers was blue, Patti's was pink.
- In the popularity poll taken by the manga's readers, Liz ranked 13th.
- When Liz was on the streets, her eyes resembled that of Crona's.
- Liz is highly afraid of anything paranormal.
- Liz can act as her sister's Meister.
- Hints suggest that Liz is older than almost every member of the main cast, however she cannot be much older than Tsubaki. In chapter 74, when the Spartoi group is in the wrath chapter of the Book of Eibon, Liz gets mocked by Patti, Kilik and Black Star for being older than them. Then, Liz points out that she is only 2 or 3 years older. Taking into account that is stated that Kilik is 13 years old, Liz should have 15 or 16 years.
- She sometimes blames Patty for her actions like when Tsubaki and Black Star returned because they finished getting Tsubaki's brother's soul she said that Patty cried when in the truth she was the one who cried.
- She scored 28 in the Ultimate Written Exam.