MBurns,
RC marriages were only recorded in the statutory marriage records from 1864 onwards. William & Margaret evidently married well before that, and so you won’t get a civil marriage certificate for them. But even if you did, they didn’t record mothers names.
I have searched the RC parish records on Ancestry but did not find their marriage. If it’s any consolation RC marriage records from that period ie 1850s, rarely have parents names. Usually all you normally get is the date, the couples names and their 2 witnesses. I couldn’t see any of their childrens baptisms apart from Patrick. Dromore RC’s records start in 1835 but perhaps the couple were living in a parish which has no records for the 1850s and early 1860s. (William was a labourer and they tended to move about a bit to follow available work).
The tithe applotment records for Crossan list Terence McBride farming there in 1826:
http://www.irishgenealogyhub.com/tyrone/tithe-applotment-books/parish-of-kilskeery.php
There were several other McBride farms in the townland. The RC baptism & marriage records for Kilskeery don’t start till 1840 so you probably won’t find a marriage for Terence, as he presumably married around 1810-1820.
In the 1901 census, there were 13 houses in Crossan, and a total population of 49 people. The various McBrides in the townland are likely to be related.
Griffiths Valuation (1860) lists Terence McBride on plot 9 in Crossan. That was an 11 acre farm. According to the Valuation Revision records on the PRONI website, it remains in his name till 1876 when it passes to Francis. That ties in pretty well with Terence’s death in 1873. The Griffiths clerks only revisited every few years and the date in their records is when they learned of a change, rather than when it actually occurred. But that, plus the 1901 census, shows that Margaret’s father was Terence McBride as per her Scottish Poor Law application.
The 1869 death certificate must contain a mistake. The lady could not be “married” and a “farmer’s widow” simultaneously. One of those must be incorrect. Probably the Registrar meant to write “Farmer’s wife”. That’s the only explanation I can offer. (Mistakes on certificates are quite common. Patrick’s marriage certificate has a mistake in that his father’s surname is given as Crosson, not McBride! However it does inadvertently tell us where he came from.). Given her age and the fact that there were only a limited number of McBrides in Crossan, I’d say it’s very likely to be Terence’s wife, particularly since he was the informant.
I can’t think of any documentation that’s likely to exist in Ireland that would show Grace’s maiden name. Scottish death certificates show both parents names, as do those of some other countries, but Irish ones then didn’t. There’s no obvious reason why Margaret should lie or not know her own mother’s name in her Poor Law application, so I’d be inclined to accept it as accurate. Not every Irish family followed the traditional naming pattern. The absence of any Graces in Patrick & Margaret’s children is not conclusive. Maybe they didn’t get on well with their mother?
The surname Stars/Starrs is common enough in Tyrone. In the 1901 census there were about 100.
Here’s Patrick Percy’s 1865 birth certificate:
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_returns/births_1865/03585/2321599.pdf
I don’t see any other children after that so he must have been the last.