The Ghostbusters first meet the Jennifer Lynch after Martin Heiss fell out of the window because of the ghost Mayhem, which Erin had released from the ghost trap to impress Martin. The agents brought the four Ghostbusters to City Hall where Jennifer Lynch with the Mayor were there to talk with them. Jennifer assisted the Mayor and explained that they were going to have to make the Ghostbusters look like frauds as the Mayor wanted to avoid mass hysteria believed to be caused if the public knew ghosts were real.
Later, after the confrontation between the Ghostbusters and Rowan, Jennifer showed up and sent them out of the building looking like they were arrested and then told the press that it was all a publicity stunt by the Ghostbusters.
After the Ghostbusters save New York, she buys them the firehouse for them and increase their funding.