Roman Catholic Church records for St. Andrew's parish show the marriage of Matthew Pentland of 16 Crompton Court; father John Pentland, mother Bridget of 16 Crampton Road and Bridget Dougherty of 21 Anglesea St; father Christopher Dougherty, mother Mary on 7 November 1880.
church of Ireland.
The marriage of Matthew Pentland Full age, House Painter Widower of 23 Nassau Street Dublin; father John Pentland, House Painter and Charlotte Kerr Full age, Spinster, father Isaac Kerr, Steward of 24 Upper Fitzwilliam Street Dublin took place on 10 November 1883 in Dublin at St. Anne's Church of Ireland.
There then follow five children#s baptisms between 1885 and 1891. The younger died first, in 1893 followed by her mother in 1899. The two girls, Matilda and Isabella were recorded as CoI in the orphanage in 1901 but with their father marrying first in the RC then CoI church I do not see what you mean by "wrong religion". No further trace has ben found of them. Matthew jnr. was resident on the cripples' home in Bray in 1901 and died there a few years later. Of John Joseph, the eldest son no trace has been found beyond his baptism. Bridget Catherine died in Dublin, a spinster, in 1958.
It is usual logical that the daughter of the first marriage would be brought up by her grandparents. This was common practice in both Scotland and Ireland well into the twentieth century. I do not see, however, where Athboy comes into the picture. As I mentioned before there were Pentlands there well into the nineteenth century but Matthew Pentland was son of John Pentland and Bridget Smith who lived in Dublin. They also had a daughter Julia who married Ernest Wilson in Surrey in 1890 and appears with him in the following three censuses. In the 1901 and 1911 censuses their niece Mary Pentland is living with them; she died a spinster in 1935 in Liverpool.
Unless Matthew Pentland lied about his marital status in 1883 the Bridget Dougherty who emigrated to the USA cannot have been his wife. All I have found for MAry Pentland's birth is the civil record but not all Dublin church records surive and even fewer have been indexed on-line.
Roman Catholic Church records for St. Mary, Haddington Road, Dublin show the marriage of Joannes Lynch, 1 Malachy Place, Father Michaelis Lynch, Mother Margarita to Maria Pentland, 1 St Mary's Rd, Father Henricus Pentland, Mother Julia, residence Athboy on 24 September 1899; Priest Hen J Lube; Witnesses Elizabetha Greene & Gulielmus Walker.
This could be where the Athboy connection comes from. It is perfectly reasonable for John Lynch's wife to have been raised in Athboy since her parent's lived there and to have gone into service in her teens, perhaps long before she was sixteen but it is very doubtful that a child in her early to mid teens would have been given the responsibility of a nursery nurse or nanny, they were usually older. It would be most interesting to know the original source of this information.
From this analysis it appears there were two Mary Pentlands in Dublin during the relevant period. One never married and her age was correctly recorded in the 19-1 and 1911 censuses as 23 and 33. The second Mary did not marry and her age was also recorded correctly as 19 and 29 in the 1901 and 1911 censuses.
The Bridget Dougherty found in the USA no doubt existed although I have insufficient information to track her in censuses. What seems clear is that she was not the first wife of Matthew Pentland nor was she the mother of John Lynch's wife.
I hope this information helps you to sort out your mystery and thank you for helping concentrate my mind as it this review has sorted out two families who were giving me problems. All I have to do now is work out who Henry Penltand of Athboy was!