Hi Matthew,
I found various siblings of your Catherine's in Ireland. It seems she was born before the Civil Registration started in Ireland.
However, it seems that her parents may be originally from Co Tyrone. At some point, they moved to Co Down.
Peter Owens born on 26 Jan 1865 in Clonavaddy, Tyrone, Ireland to the parents of Bernard Owens & Eliza Fox
(This son had passed away sometimes between 1865 & 1869)
Peter Owens 25 Nov 1869 in Downpatrick, Downpatrick, Co Down to the same parents above
Bernard Owens 8 Nov 1871 in Downpatrick, Downpatrick, Co Down to the same parents above (on the database, it leaves his father name blank? But it clearly showed his mother as Eliza Fox)
Eliza Owens 19 Apr 1874 in same location and to the same parents above
Joseph Owens 27 Dec 1879 in same location and to the same parents above
Strange birth registration--
Christina Owens 5 Jun 1874 in Downpatrick, Downpatrick, Co Down to the mother Elizabeth Owens (wondering if it is yours)
Possible baptism record but I think it is not yours because I saw other entries like this one in same area but with different mother...(in 1860s and 1870s)
Never know if there were two Bernard Owens from same area...
A Parish Baptism Entry on
John Owen
Male
Father's name: Bernard Owens
Baptism date: 14 May 1857
in Dromore Roman Catholic Church in the District of Omagh, Co Tyrone
Matthew, I think Catherine's parents were married in Co Tyrone--possibly in Roman Catholic Church--try to start with 1865 Birth Registration in Clonavaddy, Co Tyrone--to see if they have a baptism entry on him. If so, then ask if they have a marriage entry on her parents and on Catherine herself. If not, then try Downpatrick, Co Down churches.
Also, you can try and check death indexes on Peter Owens (b. 1865) to see where he died--it will help you to see where the family were--in Co Tyrone or Co Down...I think he may had died in Co Down.
As to Charles' parents--I am afraid that I could not find him without any information from his marriage certificate--it seems he and Catherine did not register their marriage OR Catherine may had previously married before that we may "overlook" her marriage to him with her married surname.
Hope this information is helpful in pointing your research in the direction.
Kind regards,
Tees