The primary difference between a "Gina" and a "Jina"? The latter tend to be more "classically" beautiful, while the former are easily described as "commercial" or "hott". Jinas are reminiscent of Marilyn Monroe, Audrey Hepburn, and/or Sophia Loren.
"I need a Jina in my life. She'd help me debate these insane republicans AND throw-down in the bedroom tonight."
Lying for no reason
Hooking up with people she normally wouldn't
Trying to get a hotel room just for the bathrobes
Other acts of drunken splendor
(Pronounced like vagina without the va.)
Jina's best friend: "What? Your 20."
Jina: "Jina is 17."
When talking about a night in first person: I hate that guy but Jina was into it so I ended up sleeping over.