Have you looked at the early census for her family, sometimes it will say more than Ireland. Naturalization papers will sometimes have a county, gravestones also are known to have
counties on them.
The enormity of the task is that there were 128 of 1,655 McHugh's in the Griffith Valuation in Galway as an example.
The Tithe records 1823-1837 in Ireland show 589 McHugh's in Ireland.
Is her mother named Susan or Suzanne? or something at least unusual. What is her father's name and her brothers and her male children called?
These would be at least be a clue?
I'm surprised at the number of Susan McHugh's in PA some actually were born after they died, you would think someone would of corrected that. None have a birth year around 1891 but 1884, 1895, 1889 etc.