She is a nurse in an ER unit in an unnamed hospital. She has had the job for three years, as she says to Carl during dates. She likes to spend her spare time at the karate dojo in Garcia, San Fierro, San Andreas. Due to her health-conscious image, she likes to eat at diners but avoids fast food restaurants. Katie also likes the shoreline and her mood improves when the player drives by the area, especially by the Gant Bridge. She doesn't like the Queens neighborhood. She is also fascinated by automobile accidents and is easily aroused by reckless driving.
It is possible to date Katie before the San Fierro area is unlocked; in fact, this can be done just after the very first mission in the game. However, it is recommended to go to San Fierro during midday hours as she's more likely to spawn then.
She can initially be found at the northeast corner of Avispa Country Club at the south end of the city, practicing t'ai chi behind some bushes. She can be seen easily from the road. Katie likes men with sex appeal and muscle, so bulk up before asking her out.
Katie lives in the Juniper Hollow district of San Fierro, at the northwest corner of the city, just southeast of the Gant Bridge and the nearest home to it. She is usually at home between 12:00 and 00:00.
There is a glitch which commonly occurs in the gameplay. If a player dates Katie in one game and starts a new game and does not date her, they can usually find after being wasted that their weapons are still with them.
Despite her dislike of the area, the Gaydar Station club is the closest dance club to take Katie to.
Katie seems to prefer areas close to the shoreline, so options include driving around the area below the Gant Bridge and Jizzy's Pleasure Domes (including the latter's parking lot), or the Bayside area across the bridge. She also loves being driven around in Chinatown. She seems to prefer a moderate driving speed; although she will at times encourage Carl to drive faster, although doing so makes her Fun meter drop. She also appears to be aroused when Carl collides with anything, although this doesn't appear to affect either the Fun meter or Progress statistic. Steer clear of the Queens area during this date as she dislikes it. An alternative less time consuming way of passing this date is to simply drive around Katie's housing block at a moderate speed and you will be sure to pass the date.
Katie will only invite Carl into her house for "coffee" when the date ends (arriving at her house) with a relationship over 52%.
- Dating Katie will allow the player to get out of the hospital for free, and they will also get to keep all of their weapons after dying, a form of universal healthcare not found in other Grand Theft Auto games (except GTA IV where you keep your weapons but still need to pay). If Carl is wasted in San Fierro he will hereafter spawn outside Katie's house rather than the hospital.
- At 50%: Katie will give the player the keys to her white Romero.
- At 100%: Katie will give the player the Medic Uniform, which consists of a white shirt emblazoned with the standard medical Star of Life and dark blue pants.
- Katie's car has a personalized license plate reading "TRAUMA".
- If the player takes her on a driving date, she will encourage Carl to drive faster, but if the player does so, the "fun" meter will go down, and text will inform the player that they are driving too fast. It's possible that she is being sarcastic.
- When Katie decides to do a driving date with Carl, awkwardly when starting (in front of her house), she will say that she doesn't like that area and sometimes says that she doesn't want to live there. Although she actually lives there, it might mean that she doesn't like her neighborhood.
- In some safehouses and other house interiors (accessible in the Burglary side mission), there is a photo of a woman with dark hair wearing a red tank top who is apparently Katie, with an unknown man by her. The same photo can also be seen in Maria Latore's apartment in Grand Theft Auto: Liberty City Stories. The man in the photo might be her brother. Also, they are in front of the Greenglass College in Las Venturas.
- During random conversations while on a date, she mentions that she's a fan of Madd Dogg, dislikes OG Loc ("OG Joke is more like it") and is disturbed by the Epsilon Program "nutjobs". She's also fascinated by death and injuries since she loves car wrecks and asks Carl if he likes to lose a limb. Some of her dialogue implies that her fascination with death even borders on the sexual (She mentions that working in the ER gives her a "thrill"), possibly explaining her arousal when CJ collides with other cars. However, she states that necrophilia is too far even for her.
- In the mobile port of GTA SA, dating Katie Zhan may be optional, since the player gets to keep all their weapons after being wasted.