On 13 October 2015 her appointment to become a life peer in the House of Lords was announced by the House of Lords Appointments Commission. She sits as a Crossbencher. On 30 October 2015, her title was gazetted as Baroness Brown of Cambridge, of Cambridge in the County of Cambridgeshire. She was elected a Fellow of the Royal Society (FRS) in 2017. In the same year she was appointed one of two patrons of the Royal Microscopical Society, the other being fellow member of the House of Lords, Baroness Finlay of Llandaff.