You could try writing to the Church of Ireland in Letterkenny for details of any burial records. 20th century chruch records generally aren't on-line. You may also have to pay a searchg fee. (The church will advise you).
I am not sure where my great grandparents are buried or indeed born but my grandfather lived in letterkenny , my father was born in letterkenny in 1910'
grand father was in the donegal militia as a bandsman! Would he have been stationed in lifford or letterkenny ive drawn a blank
Can anyone. Point me in the right direction, they would of belonged to the church of ireland