In 1597 her father, a Catholic, wrote an "Instruction to my daughter Marie Browne, in the principall groundes, and moste necessarie pointes of the Catholique faithe", possibly directing her towards the idea of becoming a nun.
The letter writer John Chamberlain described the end of her first marriage in 1616.
[2][3] Chamberlain thought that she would renounce the Catholic faith, and might join the household of Anne of Denmark as a replacement for the queen's favourite Jean Drummond, Countess of Roxburghe.
[4] She attended the funeral of Anne of Denmark in 1619, listed as the Baroness St John.
[6] His sister-in-law Lady Blanche Arundell was a prominent member of the queen's household.