There's a different postmistress there these days but she keeps the idea going.
From the nzherald.co.nz
Pillsbury officials finally delivered the message to the town's postmistress.
From the orlandosentinel.com
His wife became the first postmistress in a town of 14, soon renamed Wallace.
From the smh.com.au
Thelma was born in Hough-on-the-Hill, Lincolnshire, where her mother was postmistress.
From the guardian.co.uk
Friel's mother, Mary McLoone, was postmistress of Glenties, County Donegal.
From the en.wikipedia.org
The local postmistress tries to seal, stamp and deliver Yank to herself, but he refuses.
From the time.com
Ellen Meyer became the postmistress, distributing mail from Hasty Cottage next to the house.
From the news-journalonline.com
An unmarried postmistress attends a New York convention and meets a salesman about to be married.
From the post-gazette.com
Mary became a postmistress, Chrys was in service in Glasgow and Daisy looked after her parents.
From the guardian.co.uk
More examples
A woman postmaster
A postmaster is the head of an individual post office. Postmistress is not used anymore in the United States, as the "master" component of the word refers to a person of authority and has no gender quality. ...
A Postmistress is a female Postmaster. It has always been an informal term that is no longer in common usage. In the days when the position of Postmaster was often a part time position both a husband and wife may have taken on official duties even though only one of them was actually employed. ...