According to Philly native Mary Seaborough, who works at Cook-Wissahickon elementary, where my kids attend school, "It really can mean anything you want it to mean." Seaborough grew up in South Philly. She uses "jawn," and she helped me understand the word's versatility. It is used mainly to refer to places and things, but it can even be a person, specifically a pretty woman. "A guy might say, 'Man, did you see that jawn over there?'" Seaborough said.
Or there's Dan Kelley's article "Jawn — it's the new 'Yo'", Metro 12/1/2015:
“Creed might be the movie that introduces jawn to the rest of America,” said Taylor Jones, a linguistics graduate student at the University of Pennsylvania who uses social media to study how words, and slang, change. In the film, “Jawn” is introduced by actress Tessa Thompson, who plays the Philly-born female love interest opposite Michael B. Jordan, who plays the film’s title character, Adonis Creed. She drops the j-word, while ordering a cheesesteak — “put some peppers on that jawn.”
Some of the many other meanings of vaina in other places (sheath, scabbard, husk, shell, problem, snag, nuisance, bore, fluke, piece of luck, swindle, screw, twit, nitwit, dork, …) are listen here.