It's possible, especially if they were located in the general area of Ballintra, Donegal.
Here's what I have so far in my records:
Maggie Jane Quinn, born ca. 1875 (daughter of Patrick Quinn and Bridget Travers), married James Gallagher.
Her younger sister Mary Anne, married Johnnie Gallagher. (We believe James and Johnnie were brothers)
Patrick Quinn, born ca 1865 (son of Edward Quinn and Catherine Cassidy) married Susan Gallagher.
And scattered here and there, we also have other Gallagher names that come up.
There was also another James Gallagher who married Catherine Quinn. They lived in Ballintra, because their son was born there and baptized in 1854 at St. Bridgets Church.
Without any actual written records, it's hard to name them all. But basically, if there was a Quinn and a Gallagher together, and they lived in the region around Ballintra, Laghy, Greaghs or other near towns, they are related to me somewhere.
Does this help at all??
Patty Quinn