Thank you, Matthew...
Yes, I did warn that this was going to be a difficult search and it is proving me only too correct...
I haven't located any document from the time of the births of David (in 1832) or Elizabeth (in 1835) that show Jane either 'making her mark' or signing her name which might help completely dispel Jane and Jean (who used an X) being the same person - but I already very strongly suspect they are not one-and-the-same.
If I could figure out exactly when James and family went to Honeywood/Geeveston, I should be able to definitely confirm or eliminate a family in Melville Street, Hobart in 1843 to 1847 as being the same family.
[Massive coincidence? - the Robertsons are Mum's family; on Dad's side, my great-grandfather Shakespeare Lauritz Duus set up a bakery/coffee shop "Duus's Coffee Cafe" at heritage listed 61 Melville Street, Hobart on 25 August 1906 before moving back to Queensland several years later!]
I have always suspected Scottish heritage - my grandad Gilbert Stuart Tasma Robertson served in New Guinea in WWII proudly wearing a Glengarry rather than the customary slouch hat...
{Note to self: I must organise a clearer photo of that gravestone in the Geeveston Cemetery so I can read the entire inscription.}
All this still leaves me searching for what did happen to Jane, where James was buried and where they both came from! <Sigh>
Kind regards,
Ken.