Thanks for your continued help. The Banff baptism is certainly worthy of followup.
John Fyfe died in April 1868, according to the Arva book. His wife, Margaret, died in 1860. We know nothing of Margaret's family other than that she was born in Cavan in about 1806 (1841 Census).
John Jr was born in 1835 and emigrated to the USA in the early 1850s. Andrew William emigrated to Australia in 1856. Isabella Crawford and Samuel both emigrated to the USA (dates unknown). George Edward was the only sibling to remain in Ireland.
There are no Isobels that we know of in my family, but my great grandfather, Andrew William , and his brother, George Edward, both named their second daughter Isabella. They also had a younger sister, Isabella Crawford, as I mentioned above and in an earlier posting. So Isabella is definitely a family name in the 19th Century. John, Andrew, George and Samuel also occur repeatedly in the 19th C.