Hi
There are two O'Brien families in Mortlake Surrey on the 1861 census. Mortlake is adjacent to Barnes and the families elder children were born in Barnes. John O'Brien and his wife Mary and children live at 5 Arthur Street and Daniel O'Brien and his wife Johanna live at 4 Arthur Street. Both men are agricultural labourers which in that area at that time could be equivalent to market gardening.
The reference for the census is RG9 461 folio 83
The problem would be whereas Daniel does have a daughter named Mary, though aged only 2, John and Mary do not. They have two daughters Margaret aged 8 (who is a pupil teacher on the 1871 census in Preston Lancashire) and Johanna aged 6. Neither of the daughters of John's family seem to have had their births registered so it isn't possible to find from that source whether the daughters had two names.
Daniel and his family are still in Mortlake on the 1871 census but trying to find John, Mary and their children, including their two young sons is much more difficult unless they are Thomas and Mary in 1871 in Mortlake RG10 870 folio 39 and in 1881 widowed John with daughter Johanna as housekeeper (difficult to be sure of her age but 20 something) RG11 846 folio 21 This couple had a younger daughter they named Mary Ann.
There is an old established Roman Catholic Church in Mortlake which served the area and will have records going back to 1852 - St Mary Magdalen. The church also has a burial ground. The church's website gives online emailing facilities.
http://www.stmarymags.org.uk/about/church-history/Regards
Valda
