Sarah was born 1853 to James Napper and Sarah Farley in Ridgwick,Sussex.
James and Sarah were married in Rudgwick on 17 May 1845. There three children I know of:
James Npper - baptised 7 July 1846 Rudgwick Jane Napper - baptised 1 September 1850 Rudgwick Sarah Napper - baptised 6 February 1853 Rudgwick
The marriage cert. (1872), St Mary's Lambeth, for Sarah Napper and Richard Gravett shows they were resident in Lambeth Square which no longer exists it having been covered by a high rise building round the back of Waterloo Station. 1891 picks them up living in Mendip Rd, London (not far away).