As a Philadelphian, i can sum up the usage of jawn as: a place, a thing or a girl/woman.

For example this is a valid sentence:

“Person 1: I was at the jawn down the street when that bad jawn from up the block walked in. But she didn’t say anything.

Person 2: oh that’s a bad jawn”

Translation:

“Person 1: I was at the place down the street when that pretty woman from up the block walked in. But she didn’t say anything.

Person 2: oh that sucks”