The 1848 marriage certificate says Adam Airdrey was a farmer. As such he should be in the tithe applotment records. There is one in 1834 in the townland of Ballyraer (modern Ballyrawer). The only Adam A in the parish. So that’s likely Elizabeth & Margaret’s father. Ballyrawer is just beside, and includes, the village of Carrowdore. Perhaps 5 miles from Donaghadee.
There were no Airdrey households listed in the townland in Griffiths Valuation for 1863 indicating the family had either left or died out.
Tradition was to marry in the bride’s church so that may be Ballycopeland Presbyterian. Unfortunately it looks as though a lot of their records have been lost. They do have baptisms for 1773 to 1818, but nothing after that till 1906. The baptism records are in the Presbyterian Historical Society in Belfast. They are not on-line. You would need to contact the PHS to access them.
Marriages start in 1845 and are on-line on the GRONI and irishgenealogy sites.
I searched for possible siblings marriages but did not find any. A little information on Ballyrawer on this link: