On the death of her mother, Jane was cared for by her paternal grandmother, also named Jane. It was from her home that Jane was sent to be a member of the household of Princess Mary to whom she would become a lady in waiting. Loyal to the queen until her death, Jane was at Mary's bedside when she died in 1558 and it was into her hands that Mary placed her jewellery to be passed to her sister Elizabeth.
Considered a beauty, Jane was courted by a number of English nobles, but after Mary's death, she married Gomez Suarez de Figueroa of Cordova, the Duke of Feria who had accompanied Philip of Spain when he arrived in England to marry Mary. However, following Mary's death and the accession to the throne of Elizabeth, the duke was replaced as an ambassador and the couple left for Spain.
In 1609 the seventy-one-year-old duchess broke her arm and over the next few years her health slowly deteriorated. Anticipating death Jane Dormer wore a death's head, a terminal bead attached to her rosary and ordered a coffin to be made which she kept in the house. She was buried at the monastery of Santa Clara in Zafra in Spain twelve days following her death.