I search the IFHF's online database @ ROOTSIRELAND.IE. It has abt 20 M church/civil/census B/M/D records for MOST Irish counties, including Donegal. Records before 1863 are increasingly sparse - almost non-existant by 1800. Protestant records are the LEAST likely to have survived.
For a James Short and Eliza(beth) Shields marriage in 1826 +/- 5 yrs, somewhere in Ireland, with the parents' names unknown, I found ZERO records.