There was some justified concern at the first trailer of Ghostbusters, which revealed that the three white members of the team were scientists, while the sole black member was an MTA worker. I'm sure for many viewers that still grates, and I don't want to be the one to pish-posh their concern or frustration, but I also think Leslie Jones's character ended up being much more nuanced and three-dimensional than first appeared.
Whereas the other three ghostbusters are in it for science and necessity (having just lost their jobs), Patty joins because she a) knows she can contribute something important to the dynamic and b) is a decent person who recognizes a serious problem that needs fixing. In fact, the entire plot hinges on the fact she leaves her booth after realizing one of the commuters has left the platform and gone onto the subway tracks.
It's there she sees her first ghost, and has the initiative to call it in.
She knows her own worth when she sells the others her education in municipal history, and throughout the investigation she constantly provides important information on various New York landmarks. She saves Holtzmann's life with one hand while fending off a possessed Abby with the other. She provides the team with transport and jumpsuits and encouragement. She even comes up with the idea to drive the car into the vortex in order to close it.
Patty is brave and enthusiastic and altruistic and intelligent and wears fabulous earrings. I'm so profoundly relieved that she ended up being so much more than the trailer portrayed her as that I just had to make her Woman of the Month.