Hello - I've had a quick look online for civil birth records for a Margaret Regan in Skibbereen. There were two born in 1885 in Skibbereen but only one was in the Jan - Mar timeframe (the other was in July).
Margaret Regan born 16th January 1885 in Moyny, Drimoleague in the Union of Skibbereen in County Cork to father Cornelius Regan, a farmer, and Johanna Regan, formerly Kane.
I hope that information is helpful to you.
All the best,