Sarah Knox 1817-1890 , Jane Knox McFall 1815-1891 and husband Robert McFall 1813-1890

Eleanor,

Statutory marriage registration didn't start in Ireland till 1845 for non RC marriages and 1864 for RC marriages so if Jane & Robert married in Ireland in the 1830s they won’t be in the statutory records. You may find a church record but not all churches have records for that period and of those that do, not all are on-line.  Unless you had knowledge of where and when they married in Belfast you would have to slog through 50 or 60 sets of church records. 

I note that you say that the family were Protestant. Knox is certainly a name commonly found in Protestant families in Ireland. However McFaul/McFall is almost exclusively Roman Catholic. So possibly this was a mixed marriage, with the husband adopting the bride's denomination? (I looked in the 1901 census for Co Antrim – which includes Belfast – and there were 130 McFalls. All were RC).

The surviving RC records for Belfast are on-line on the natioanl library site. (One of the main churches – St Mary’s has no records for the period 1784 – 1867 so that leaves a major gap). However I did not find a baptism for a Robert around 1813 in the records for St Patrick's which do still exist.

Dear Elwyn

Thank you for your helpful information particularly about the derivation of their surnames.

I suspect I'm not going to find their marriage as I don't have enough information to locate their parish and the possibility of a mixed marriage hadn't occured to me.

Robert and Jane are my maternal 3 x great grandparents and that side of the family were all Presbyterians so I jumped to the conclusion that they were !!

Also, according to the UK census records, they had regular visitors from Ireland so perhaps I may be lucky enough to narrow down where they came from in Belfast.

I'm still on the trail

Very best wishes from Perth Western Australia.

Eleanor