What I've found:
She was born in Dundee in June 1839, the first child of Patrick Cassidy and Mary Connoly, who were married in 1838. The birth is in the St Andrew's RC, Dundee, records

She had at least three siblings - three surviving anyhow. They were James ( 1841), Mary (1843) and Elizabeth (1848). She and her parents are in the 1841 census, though a bit messed up as her name is reported as 'Conley' instead of Cassidy. James and Mary were, like Margaret, born and baptised in Dundee - all in the RC records. Elizabeth was born in August 1848 and not baptised until October - the birth being (probably) in Balmerino and the baptism Dunfermline.
In 1851 the family are in the borders, at St Boswell's in Roxburgh. Patrick (Peter in this census) is a railway labourer, which fits with the information I had (even though the informant on Margaret Cassidy's death, her partner Thomas Lynch, gave her father's name as Michael not Patrick).
By 1861 Patrick is out of the scene - he has probably died - and Mary and her children James, Mary and Elizabeth are back in Dundee. James is now a mason, the girls are mill workers. (I have found a possible census entry for Margaret but can't be certain about this.)
In 1871, Mary is in Dundee with her youngest daughter Elizabeth... by 1881 Elizabeth is on her own.
James married Ann McIntosh in 1863* and they are in the 1881 census with children James (16) and Peter (14), James senior being still a mason.
And all this was enabled (via various search sites) because of the RC Dundee records coming onto SP!
But now - I'm stuck with the previous generation, because Patrick/Peter Cassidy seems to have died before 1855... and, oddly, I can't find the death record for Mary Connely or Cassidy. (And I'm obviously using wildcard searches on these names.. She lived until at least 1871, and possibly whoever recorded her death got her birth surname wrong, so there's a bit of guesswork needed here too.)
However - here's tae them! A whole set of connections of whom I'd no knowledge. And I'm wondering if there are descendants of James Cassidy out there - or even on this forum?
Jenny
*Just fixed typo on James's marriage which had predated the event by two centuries!
