Hello Jill, I have just checked my tree for that period but no Isabella that I can see.
I do have connections to the Kewleys through the Corrins also, but not that particular Thomas!
I understand that 'Corran' has the same derivation as 'Corrin' also coming from the Norse, but there certainly seems to be many more thousands of Corrins to sift through on our journey of discovery.
Nice to hear from you,
Regards,
Marjery