She was the first Englishwoman known to have written a full length play. And reading John Calvin converted her from being an Anglican into being a Catholic.
The first generation of English Protestant women came from a late medieval atmosphere of many highly educated women, even among farming families. Elizabeth Tanfield grew up a generation later, when very few women were being educated. Fortunately for her, her father and mother liked books and wanted her educated. She became a polymath (mostly teaching herself to read several languages), and had to be forbidden the use of candles at night, because she would just keep reading.
At the age of 15, her parents made an advantageous marriage for her with Sir Henry Cary (later Viscount Falkland). However, it would seem that they were either geeky themselves or not very careful. Her mother-in-law announced after the wedding that she would not be allowed to read books.
So she wrote poetry instead. A lot of it.
At age twenty, her brother-in-law started talking to her about his travels in Catholic countries, recommending books, and then lending them to her. She read secretly and critically, and then converted. Her conversion led to a bitter dispute with her husband, who threw her out and left her to starve, with no access to the kids. (Totally legal, once she became a Catholic.) She eventually managed to get custody of all her daughters and two of her sons. Six out of ten of the kids converted to Catholicism.
Her play is called The Tragedy of Mariam, the Fair Queen of Jewry, and it’s based on the story of Herod’s second wife. It came out in 1613, and is dedicated to her sister-in-law, also named Elizabeth.
You can read the play here.