What's cool about her? She is the first person since Ancient Rome to bring theatrical literature back to life in Europe. She was a nun who lived in a 10th century commune of women, thus allowing her time and independence to pursue her own educational goals and creative pursuits -- so long as they were an extension of her faith. Many of the plays she wrote were a Catholic response to the works of Roman playwright Terence. She retold the stories of the saints, and created female characters of strength and intelligence.
Her origins are shrouded in mystery and rumors... one of my favorite being that she traveled to a South American colony to serve as a spy, hired by Charles II. (She did perform spy duties in the Netherlands... and records indicate that the king failed to pay for her service.)
Since the life of a spy didn't pan out, and since her husband passed away, she was forced to make end's meet by writing for the stage.
Here's an energetic synopsis of one of her most successful plays: The Rover.
During the Restoration, female playwrights -- such as Mary Pix -- became less of a rarity.
This might have been because theater goers at the time cared more about the performances and less about the playwrights -- in fact, playwrights often went unaccredited (though not unpaid).