Selina TONKIN was also from St Buryan - baptised 1 Nov 1840 parents James and Elizabeth father Lab of Churchtown.
1841 at Tregunno in Sancreed HO107/144/14 Folio 25 Page 7
James 42, Elizabeth 44, Elizabeth 14, Mary 13, Martha 10, Honnor 6 and Celenia 7 months
Families arrival a couple of years before John and Prudence and family.
http://www.slsa.sa.gov.au/fh/passengerlists/1847BritishSovereign.htmBISA - suggests John and James were brothers
TONKIN John parents Richd and Honor nee GUY born 1810 Penzance Cornwall died 2 Apr 1865 Dairy Flat SA buried Yankallilla SA arrived 1849 aboard the
MARION 0ccupation Farmer residence Magill, Dairy Flat, Yankallilla religion BC
married Cornwall Prudence nee TRENOWETH who was born 1810 in Cornwall and died 23Jan 1896 Dairy Flat SA children Prudence (1830-died infant), Joseph (1831-died infant), John (1835-died infant), Jas about1837, Mary JEFFERY about 1838-c1878), Jane PEARCE (1840-1924), John Chas (1844-1934)
http://www.slsa.sa.gov.au/fh/passengerlists/1849Marion.htmTONKIN James parents Richard and Honour nee GUY born 28 Aug 1803 Cornwall and died 8 May 1880 buried WTC arrived 1847 aboard the
CRESSYmarried England to Eliz who was born about 1793 died 14 Oct 1871 buried Bullaparinga SA
children Martha DE CAUX 1828-1903, Honor/Hannah MURDOCK c1830-1908. Selina JEFFERY, William Doble
1840-1912
Now I can see William Doble does not belong with these girls. His family did arrive on The
CRESSYhttp://www.slsa.sa.gov.au/fh/passengerlists/1847Cressy.htmHe was baptised in St Buryan also parents James and Nancy
That family are in St Buryan in 1841 HO107/141/9 Folio 59 Page 18
James 35, Nancy 40, Joseph 11, Richard 7, William 1 Henry 4 along with Mary HUTCHENS 80. (Nancy was Nancy HUTCHENS)
(certainly a mix up with the BISA entry for James.)
Selina's older sisters all married at St John in Adelaide. James died at Yank in 1880 aged 86 and Elizabeth in 1871 aged 78 so it looks like he was not your John's brother.
Seems extended family emigrated. I see John's brother Enoch also emigrated
BISA
TONKIN Enoch parents Richd and Honour nee GuY born 19 July 1797 Penzance Cornwall and died 9 Jan 1875 Torrens Vale SA arrived 1840 aboard the
JAVA 0ccupation Carpenter, Farmer residence Adelaide, Magill, Torrens Vale, Yankalilla religion Methodist
married about 1825 Cornwall to Betsy nee HUTCHENS who was born about 1800 cornwall and died 10 Nov 1875 Yankalilla SA
children Wm Hutchens 1825-1864, Amelia W. CORD, JERRAN 1826-1899, Eliz TONKIN 1829-1900, Chas 1831-1855, John 1833, Mary Ann 1834-1836, Jas 1836-1923, Mary Ann Doble 1837-1855, Thos Henry 1839-1871
http://www.slsa.sa.gov.au/fh/passengerlists/1840Java-PassengerLists.htmCheers Kris