Daughter and co-heiress of Sir Roger Lewknor (b. 1465 - d. 15 Jan 1543) and wife Eleanor Touchet, daughter of John Touchet, Baron Audley, and Anne Echingham, sister of James Touchet, fourth Lord Audley. Jane's father remarried twice and had three daughters by his third wife who were half-sisters and co-heirs with Jane: Catherine (who married William Morgan of Chilworth); Mabel (who married Anthony Stapley of Sussex) and Constance (who married Edward Glentham)

Her first husband was Sir Christopher Pickering of Ellerton (b. 1490 - d. 7 Sep 1516). Jane's second husband was Arthur Pole, son of Margaret Pole, Countess of Salisbury, whom she around 1526. The couple had at least four children: Henry, Jane, Margaret, who married Sir Thomas Fitzherbert, and Mary, who married Sir John Stanley.

When Arthur died, Lady Salisbury and her son, Lord Montague, did not wish Jane to remarry, which would deprive the Pole family, and Arthur's heirs, of her fortune. They coerced Jane to become a novice at Syon Abbey. Jane was eventually released from her vows by William Barlow, the new Bishop of St. Asaph, who was residing in his priory of Bisham. She said to Bishop Barlow, 'Can I leave the veil at pleasure?'; 'Yes, for all religious persons have a time of probation. You are only a novice and could leave your nun's weeds at your pleasure. I bind you no further...', he said.

In 1539, Jane married Sir William Barentyne, Sheriff of Oxfordshire & Berkshire. Their marriage was declared void by the consistory court of London on 15 Dec 1540 because of Jane's vow of chastity. The Barentynes' sought and received an Act of Parliament to declare their marriage valid and their children legitimate in 1544 after the passage of the Act of the Six Articles. Jane died 12 Mar 1562/63. Despite the passage of this act (34 and 35 Hen. VIII, c.1543/44), Jane and William's sons were still trying to secure their inheritance in 1563.