If records have survived you can try this website for baptism and marriages www.rootsireland.ie
With both parents names you will be able to find siblings as well.
Honora/Ann Laughlin is probably a married sister!
Denis 80 Widower @ 27 B7 Ballymunterhiggin, Bundoran
I can't connect at this time to the Donegal telephone book but ou should be able to find any Dolan's in the right area.