I think they are transcription errors. Ann Evison is the mother of the children.
Lonan MI
Old Yard U 2
Sacred to the memory of Robert Tate son of
Godfrey and Ann Tate alias Evison who
departed this life 8th September 1852 aged
26 years
also Ann Elizabeth relict of the above Godfrey
Tate Ballameanagh Beg who fell asleep in
Jesus 15th September 1876 aged 71 years
Having a desire to part and to be with Jesus
which is far better
also in memory of Catherine Traylen daughter of
Godfrey Tate who died March 12th 1899 aged
73 years
also in loving memory of Elizabeth Tate daughter
of the above born May 5th 1843 died August
19th 1899

I have that he was first md Ann Banks from 1812-1820 and they had 2 children who survived and 1 or 2 who died in infancy.