I have done quite a bit of research on Drennans back to James Drennan who married Eliza Hayden. I have been trying to find a connection to Dr. William Drennan but have been unsuccessful so far.My father in law was David Drennan youngest son of George Drennan and Eliza Ann McGarrell. George was the son of James and Eliza. David became a Presbyterian Minister in Australia and married Edna Zoe McCulloch from Tasmania. They had one son, Brian Richard, and we were married in 1965 and have 2 sons and 2 daughters. Bailey, I think your grandparents - George and Lilian - stayed with us in Ballarat some years ago.