The world state and the USA elections preoccupied me for some time, but I did find the arrival for the Pilgrim in a San Francisco paper. as follows
Shipping intelligence
Port of San francisco February 5 (1850)
Arrived
British barque Pilgrim Francis 77 Days from Auckland, with 54 passengers
Unfortunately that is all there was and there was nothing about the passengers except the number. Still looking for what became of Mary Georgina Scott. Not mentioned in the Probate for her Brother John Sampson, died san Jose 1850. All Mary's living sisters petitioned for a distribution from John's intestate estate but Mary Georgina was not one of them. Her husband John was in Marysville Yuba, County California during this protracted probate, but later married as a widow, in England, 1854. So, it comes back to where and when she died. Between 1849 after leaving Pitcairn, arrival in San Francisco on 5 February 1850 and John Scott signing papers for John Sampson Probate in Marysville 26 September 1850.
My original estimate of arrival was based on the entry of Walter Broadie's diary about Pitcairn, and was written retrospectively, so incorrect for timeframe. So, the question still remains. At sea? In San Francisco, or somewhere between that town and Marysville.