There are at least 10 McCaughan's living in Ballycastle according the northern ireland - british telephone book.
These come will full addresses and postal codes.

Catholic or Protestant?

Northern Ireland has two sources of birth/baptism records

www.emeraldancestors.com

Also an Irish History Foundation. This is a not for profit but fee paying website to which Antrim is a memberDudley.

I would imagine the children John and Hugh would marry in the 1860's? and their children might be on the website
www.familysearch.org which has civil registrations listed
from 1864-1950's.

I think it likely the only way to get Charles wife's name is the birth of either John or Hugh. I would use Hugh to
search as it is relatively different whereas John is the most used name. You can search the Foundation just with the name Hugh and birth year +/- and get a record with parish/place, mother's fore name and maiden name and date.
Once you have both parents names you can search for siblings. The Parish Ramoan isn't listed but could also have another name or be amalgamated with another parish.

Ballycastle is a Poor Law Union or later Civil Registration District, and a Town in the Parish of Ramoan.

It is located up by the 'Giants Causeway'.There is a Church of Ireland church in the middle of the main square -
Holy Trinity

These are some of the results from www.familysearch.org

Charles age 97 died April-June 1919 birth yr est. 1822

Charles age 78 died Jan-Mar 1882 birth yr. est. 1805

Charles age 87 died Jan-Mar 1882 birth yr. est 1798

Charles age 78 died Jan-March 1883 birth yr. est 1785

Hugh age 71 died Oct-Dec 1913 birth yr. estimated 1842

Several Sarah's just a guess that she may be named after her mother.

Sarah age 80 died Oct-Dec 1878 birth yr. est. 1798

All the above are Ballycastle.

Year of birth determined by age given at death.Sometimes
in Ireland that was up for speculation with sometimes 5 yrs
difference from reality.

Annette Code