Mrs. Nelson wears a skirt, usually blue or black, a magenta v-neck shirt, and a white undershirt. She also wears black, flat shoes and a small wrist watch. She has black hair, which she styles in a bun, and black eyelashes.
- "The City Part of Town" - First speaking role as the Fourth Grade teacher.
- "Truth and Advertising" - Second speaking role.
- "Skank Hunt" - Seen speaking with police officers in the school hallway.
- "Douche and a Danish" - Seen trying to teach class when Mr. Garrison barges in and tries to teach.
- "Hummels & Heroin" - Oversees Marcus Preston's presentation in the school cafeteria.
- "SUPER HARD PCness" - Attends school staff meetings.
- "Dead Kids" - Hands over math exams to the students and explains them again the addition of fractions and later seen being interviewed by police about one of the school shootings.
- "A Boy And A Priest" - Seen in church.
- "The Problem with a Poo" - Watches Mr. Hankey leave South Park.
- "Buddha Box" - Pulls the Buddha Box off Eric Cartman's head.
- "Bike Parade" - Seen watching the bike parade.
- "Shots!!!" - Seen at the PTA meeting.
- "Let Them Eat Goo" - Eat a Tegridy Burger in the middle of the class.
- "Tegridy Farms Halloween Special" - Seen at the school assembly.
- "Turd Burglars" - Seen at the women's meeting at Park County Community Center.
- Mrs. Nelson is the third teacher to teach the same 4th Grade class. The first being Diane Choksondik and the second, Mr. Garrison.
Liza Nelson | Mrs. Nelson
|South Park Elementary Staff|
|Richard Adler | Mr. Derp | Mr. Garrett | Mr. Mackey | Mr. Meryl | Mrs. Nelson | Mrs. Streibel | Mr. Venezuela | Mr. Wyland | Mitchell | Pearl | Recess Supervisor | Girls' Volleyball Coach | P.C. Principal | Strong Woman|
|Chef | Mr. Conners | Ms. Choksondik | Ms. Claridge | Ms. Crabtree | Ms. Ellen | Mr. Garrison | Mr. Marsh | Mr. Slave | Ms. Stevenson | Principal Victoria|