Best answer is I don't know.
I wonder if it was a transcription error on Thomas' baptism?
I don't see a marriage for James & isabella Corlett.
I thought Isabella Callister Quine died in 1853.

Looks like we need to view the wills of James in 1841 Lonan and Isabella in 1853 Lonan.
CAIN, James 1841 Lonan E 2 0106416
CAIN, Isabella 1853 Lonan E 72 0106454

Lonan MI
Old Yard A 15
In memory of James Cain who departed this life
June 14th 1841 aged 60 years

Lonan MI
Old Yard
E 22
Weathered stone
In memory of Isabella wife of James Cain who
departed this life April 15th 185... aged 75 years
also Isabella Jane daughter of Thomas ............
...................................................................... ...

DJD