Unfortunately a bank transfer is the worst payment method in these situations.
Is this person still on Facebook. If so leave her some bad rep to warn others.
Its worth chasing it with your bank on the off cchance they will do something, but it unlikely.
This may seem daft but report it to your local police. They enjoy policing social media sites, as it easy for them to do from their chairs!
I wish you luck and hope you get your funds back 🙂