In the 1871 census, one of Philip and Elizabeth Comish's children with them in Lezayre was Mary aged 14, born Patrick. Philip's widowed mother mother was living with them and her given name was Christian.

In 1881 Mary was a nurse (age 23) in a houshold in Bride.
Both Brian Lawson and the IGI have a daughter for Mary Comish, (Catherine Selina, christened Lezayre Jan 25 1885).

Ancestry.com has transported parts of Lezayre to Wales in 1901.
Here we find Philip, 70 Elizabeth 60, and Catherine (granddaughter age 15) at Ballamanagh, Lezayre.

There is no Catherine Comish who would fit in the 1891 census.

Possibly Catherine and Christian are one and the same.