The civil marriage record indicates that Mary Purcell's father was Matthew Purcell. I located an 1864 civil birth record for a Mary Purcell with father Matthew and mother Anne Byrne.
Very likely Mary made herself younger on the census returns.
I did find a February 15 1855 marriage record in Leighlinbridge RC church between a Matthew Purcell and Anne Byrne
If this is the correct family then there were at least four other siblings: James 1856 Julia 1858 Thomas 1861 Anne 1867
I also found an 1866 civil birth record for a Charles Fitzpatrick with father John Fitzpatrick and mother Bridget Doyle. The family lived in Carrickslaney townland Bailon civil parish.
Charles was the eleventh of twelve children.
John 1847 Catherine 1848 Ellen 1850 Laurence 1852 Edmund 1854 Patrick 1856 Honor 1858 Bridget 1860 Michael 1862 Henry 1864 Anne 1867All baptisms in Ballon RC parish
The parents were married July 8 1846 in Ballon church.