Hi Annie
I too checked all Catherine Wishart's on IGI, Scotlands People and the Census and have spent the past 2 days of Christmas away with family. Before I left I'd checked all 6 of the possibilities I found and slowly eliminated them. This left only 1 possibility and that is the first one which dee melody mentioned i.e. Catherine, b.11/9/1838, bp.14/10/1838 Clackmannan, Clackmannanshire dau. of James Wishart and Jean Walker. She was in fact a twin of Elizabeth.
The IGI shows that James Wishart and Jean (or Jane) Walker married 8/11/1828 at Logie, Perth. Their children were:
James bp.7/6/1829 Clackmannan, son of James Wishart and Jean Walker (he died)
Janet (as Whishart) bp.28/5/1831 Clackmannan, dau. of James and Jean Walker
Anne b.4/8/1833, bp.25/8/1833, dau. of James Wishart and Jane Walker.
David b.24/8/1835, bp.6/9/1835, ditto
John b.22/9/1837, bp.18/10/1837, ditto (he must have died also)
Catherine b.11/9/1838, bp.14/10/1838 Clackmannan, dau. James Wishart/Jane Walker
Elizabeth b.11/9/1838, bp.14/10/1838 ditto
James b.13/9/1840, bp.4/10/1840 ditto
1841 Census - Clackmannan, Clackmannanshire - indexed as Wickert/Wickart
James 33 Not born in County
Jane 35 ditto
Janet 10 Born in County
Anne 8 ditto
David 5 ditto
Catherine 3 ditto
Betsy 3 ditto
James 8 mos. ditto
1851 Census - Alloa, Clackmannanshire
James Wishart 42 Ag. Labourer b. Tulliallan, Perthshire
Jane Wishart 50 b. Falkirk, Stirlingshire
Catheran Wishart 12 b. Clackmannan, Clackmannanshire
Elizabeth Wishart 12 ditto
James Wishart 10 ditto
1861 - Tillicoultry, Clackmannanshire
Jane Wishart Head Widow 58 Wool winder b. Falkirk, Stirlingshire
Janet Wishart Dau. Unm. 28 Finisher of Woolshawls b. Clackmannan Parish
James Wishart Son Unm. 20 Woollen Weaver b. ditto
Jane Wishart g/dau. 9 Scholar b. Alloa
David Wishart g/son 7 Scholar b. Tillicoultry
Ann Wishart g/dau 2 b. ditto
Janet Kemp - Unm. 59 Woollen Winder b. (?), Stirlingshire
This latest census shows Jane was widowed between 1851 and 1861 - cannot find on SP between 1855 and 1861 so presume he must have died 1851-1854.
Suspect that all of Jane's grandchildren were probably children of her dau. Janet although can only say for certain that the youngest Ann was (on IGI).
So, Catherine Wishart was a twin (cannot find her twin in 1861 nor any likely marriage so wonder if maybe Elizabeth Wishart also went to Tasmania ??) If Catherine went to Tasmania in 1855 looks like it was shortly after her father died.
Her mother Jane/Jean died 10/5/1874 aged 72 at 24 Stirling Street, Tillicoultry. The informant was her son but can't tell from initial whether David or James - he was a Carter living in Airdrie. Her parents are shown as David Walker, ploughman (deceased) and Janet Walker M. S. Syme (deceased).
Both these parents births appear on the IGI.
Will now try to see if I can find a possible Samuel Upton though feel this is likely to be far more difficult.
Annette