I am wondering if your Davins have any connection to the Davins in the US 1880 census in Palatine, NY.
Parents John Davin and Bridget (Connelly) born in Ireland,
children
Delia (b PA)
Michael (b PA)
Thomas (b NY)
and Mary (b Ireland, living next door).
I believe they came to the US in early 1860's.

Someones website lists the parents John and Bridget as being born in Clifden, Co. Galway.