Have you noticed that in the 1861 census, it says that Sophia is "wife of T Gallichan Hospital Steward"? And the 1871 for him just says "Policeman".
In 1851, Thomas's address is the District General Hospital and Workhouse, his relation is Warder of the Insane, and his occupation is "Public Meter" (which is how I read it, and it seems clear). Presumably he was on duty overnight. Rather oddly, the person who filled out the schedule seems to have assigned people their current occupation as their relationship to the head, and some former occupation as their occupation; for instance, the last person on the page has "Gate Keeper" as relationship, and "Shipwright" as occupation. Ah -- possibly people did night duty as well as having a day job? A night-time gate keeper, for instance, could sleep on site and just be present if needed.
In 1861, both his relation and his occupation are "Keeper of Lodges", at District Jersey General Hospital. That fits with the description of him in Sophia's 1861 entry.
Just to note that in 1851 she is actually 28, and Anc'y has transcribed her surname with one "L". And in 1861 it calls her "Gallichio". Her place of birth is given as Ireland on all three censuses.
The eldest child in the 1851, Louisa Ann, was aged 9 and born in St Helier. Is it possible that Sophia and Thomas married in Ireland, for instance if he was in the military and posted there? It was pretty common for men in the British military in Ireland to marry Irish women.
There is really an astounding number of Thomas Gallichans and Sophia Gallichans in Jersey!
Have you established that the oldest children were children of this couple? I'm just wondering, given that he was 12-13 years older than her and, at 28, she was only 19 years older than the eldest child in 1851 (when the children are 9, 7, 5 and 1 - a possible gap there before the last one, although the 5-yr-old is named Sophia), whether maybe he was a widower with children when they married. For them to have married in 1839/40 -- she would have been 15-17 and he would have been 28/29 ...
"Sophie" would have been very unusual for an English-speaking woman at the time; Sophia was a relatively common name.
In 1841 there is a Sophia Nield in St Saviour, a female servant aged 18 shown as born in Foreign Parts. I might think she was as likely Irish.
Have you traced the other similarly-aged Thomas Gallichans forward from 1841? (Or just identified yours in 1841?)
Thomas 1811 in Trinity with daughter Fanny is accounted for in 1851, widowed.
Thomas 1811 in St Helier with wife Jane and daughter Louisa is accounted for in 1851.
Thomases 1811 in Trinity with wife Elizabeth and son Thomas aged 1, carpenter, is Thos Mallichan, farmer & carpenter, in Trinity in 1851.
I'm not managing to account for the fourth in 1851; in 1841 he is Thomas Gallichan 1811 in St Helier, shoemaker, with wife Elizabeth, 25, and children Thomas, 6, and Elizabeth, 2, and I don't see any of them.
There is a widowed Elizabeth Gallighan 1815, sick nurse, in a wealthy household in St Helier in 1851. She could be the wife of that last Thomas in 1841.
What's interesting in 1851 is that Clement and Jane Gallichan in Trinity, with whom the other Thomas, carpenter, and Elizabeth were living with a Thomas aged 1 (them being accounted for in 1851), have with them in 1851 a Thomas aged 15, i.e. of an age to be the son of the other Thomas and Elizabeth. He is identified as son, but he doesn't match the Thomas aged 1 in 1841, who is, I think, accounted for in 1851.
It is possible that Elizabeth the sick nurse was not a widow, and your Thomas and Sophia were not married because he was previously married, and his former wife did the respectable thing and called herself a widow. These things happened not uncommonly.
