Hi Joe,
As guesstimates go, no problem there. Is there anything in US records to confirm Jessie was born in 1828, or does this come from the Clontarf marriage record?
Hallmark, re the Scottish records, all Joe has to go on is her name, a putative father, John, army officer, from the Clontarf records. Going by the 1841 census, there are dozens of candidates for a Baptism record, unless Joe finds that only one or two have army officer fathers. He may be lucky as I couldn't find any at all in the 1841 census, - several army pensioners, and the one sargeant at arms. Might be worth spending the few bob to look, Joe.
The identification of the first sillouette as c.1830, origin British Isles - I did email it to someone expert in these things -means it cannot be of anyone born 1828. I think it would be well worth looking at the other items for dates especially the portrait and the ring, for further clues.
Hallmark,My view on Lady Ann is slightly different from yours, in that there was one individual who would formally be called Lady Clontarf in the historic record - the wife of Rawson, Viscount Clontarf.
Debrett,the Bible of UK Titles says:
This the fourth grade in the peerage. A viscount is, in conversation, referred to as Lord (Chelmsford) rather than the Viscount Chelmsford
The wife of a viscount is a viscountess and is known as Lady (Chelmsford). Use of the title viscountess in speech is socially incorrect unless it needs to be specifically mentioned, for example in a list of patrons.
http://www.debretts.com/forms-of-address/titles/viscount-and-viscountess.aspxI am not saying this Lady Clontarf is the one Joe is looking for, merely that there is no myth - there was a historical lady Clontarf, just earlier than Joe's guesstimates, and in my view, oral history can often have a grain of truth and a distortion of time combined. It is 160 years since that wedding in Clontarf. Joe's family history is that the portrait is of Lady Anne, and a date on it would be very helpful in evaluating this hypothesis. Hairstyle, dress, pose, ornamentation etc, might give clues.
However it might be worth Joe starting another thread on Scotland General giving the Clontarf marriage details and seeing if anyone can help him find that JS?
Joe, I know this is very frustrating, it seems to me that no Lady Clontarf is on offer for the dates your guesstimates give, allthough there are several relatives of the only person who would have been called Lady Clontarf, who are wives or daughters of Earls, with the name Ann or Anne in the area for the period you estimate.