Actually, there have been quite a few short stories published since 1980 (when I began reading SF and fantasy magazines, and purchasing anthologies of SF , fantasy,and/or horror)that have combined Jane Austen and fantastic tropes. One recent one (2007 or 2008, F & SF magazine) had Mary Austen meet Dr Victor Frankenstein. Susanna Clarke did several short stories about the Austen sisters using paranormal powers and espionage to bring down Napoleon Bonaparte. And Clarke used a "Mrs Bullworth" who was an obvious parody of Mrs Rushworth from Mansfield Park in her great novel, Jonathan Strange and Mr Norrell.
Now that I think of it, zombies and Mansfield Park would be a pretty good fit...
Change Mary Austen to Mary Bennet. Darn it!