Thanks, I subscribe so I'll do a bit more searching. An update since I also had some advice from another group:
This was my reply:
Since I posted I have trawled records and found a marriage for John Swalthy and Elizabeth Barry so now have:
John Swelthy to Elizabeth Barry on 28th Sept 1794 at St. Mary's, Cork
Their children: William baptised 15 Aug 1797 St. Mary's Cork
Margaret baptised 12 Aug 1804 St. Catherine's, Dublin
Bartholomew baptised 14 May 1809 St Catherine's Dublin
Elizabeth baptized 26 July 1812 St. Catherine's Dublin who married Patrick Gallagher b 1799 then moved to Manchester England.
I am concerned to have the right family. Do you agree that the above is likely to be the one family. I am about prepared to accept they are.
How all the others fit in, I'm not sure. I have looked at the marriage of Margaret Swalthy and William Buckley and while the dates fit I'm can't think why she would go back to Cork as she was born in Dublin. It's feasible, as it is about the time I would be expecting Elizabeth and Patrick Gallagher to marry - perhaps all the family were on the move and they had relatives back in Cork.
Regarding Elizabeth Barry who married John Swelthy: I have found a baptism on 30th June 1770 with father Gerard Barry and mother Elizabeth Locke -these dates seem to fit and then I found marriage: Gerard Barry to Elizabeth Locke 11 June 1769 St. Peter & Paul, Cork.
I don't know where Margaret Swalthy who married William Broderick fits it. 'Swalthy' seems an uncommon name but I've found quite a few in 1700's and can't work out how they are all connected.
Thanks for your assistance, it's helped me push on and any other advice greatly appreciated.
Maura