Think I found the location - it's seems to have been the site of a Holy Well and later a small village within a townland so doesn't appear on the townland database.
The older maps show the village as 'St. Peter's Well' and it's located on the borders of several townlands - Cuilmore, Lissadoill, Gardenblake Commons and Cappard Demesne.
see : http://goo.gl/mRGqZ
(c1837 OSI Map)
The location is about 9km north east of the town of Gort, and all the townlands mentioned are in the civil parish of Kilthomas, and split between the Poor Law Unions of Gort & Loughrea - most being in Gort. (Registration districts usually equate to Poor Law Unions)
p.s. found the family on the 1911 census - married 10 years so c1901, Martha and all the children born Lancashire, so expect that's where the marriage took place.