In the 1881 census Isabella was living with George in Marsh St. Dalton in Furness -up from Barrow in Furness-, also there were children William , John ,Stephen and Caesar Moore. These were the children of John Moore and Isabella.
Her single name was Kermeen and she came from an area around the Dhoon. Her parents were John and Ann Kermeeen and she had 5 sisters and a brother Robert who was still there in 1881 at Thallow Mitchell.
Her father was part of a large family that worked on farms around the area such as Ballalin, Ballig and Ballaberna. Three brothers of John also had large families so there was quite an enclave of Kermeens at this spot.
Isabella had other children to John Moore when they lived at the Dhoon but there is no obvious record of her marriage to George on or off the Island.Since Caesar was born in Askam (Askham) in 1879 and she was using the name Cowley by 1881, in between is your search but there may not be an answer.

Len Faragher