"Shit! Get us out of here alive, Huang, and I'll marry you! Yes - I know about sarcasm."
―Ling to Huang
After Huang Lee arrives in Liberty City, he gets an order from his uncle Kenny to find a crew that was watching a group of undercover cops spying on an "exotic movie" he is financing. When Huang arrives there, he finds out that Ling was the only survivor of an LCPD attack. After a quick talk, the police arrive again and Huang loses the heat, and then drives to his apartment. Huang offers Ling "coffee" but she declines his advance. Huang then asks her whether she was an observer or actress in the movie, to which she tells him to "Keep it in his pants" and that she'll see him around. Ling then drives the car back to Wu Lee.
"Ling... What the fuck?!"
―Huang to Ling after her death
Ling then got an order to teach Huang combat and to wield a weapon. After doing so, they protect a shop from thugs. However, Ling is swiftly shot by one of them, and dies in an alley. An ambulance is used to transport her away at the end of the mission as depicted in a cutscene.
Viewing the note for replaying Under the Gun through a mission replay whiteboard in safehouses reveals that Huang is saddened by her death, writing that he'll miss her.
Despite being one of the main marketing images for the game (her artworks in a red dress), her role in the game is relatively small. This can suggest that she originally was supposed to have bigger role in the game, as characters having many artworks often have a bigger role in the storyline.
According to the game manual, Ling's number is 555-232-6666.