Looking For Fitzgeralds

Hi. I'm looking for relatives of David H. Fitzgerald, born October 1866. I've found a citation for what I think is an older brother, John Donohoe Fitzgerald, born and baptised in 1848 at St. Andrew's.

I think their father's name was John David Fitzgerald and their mother's name was Rose.

I also believe that the sons, John D and David H, had another brother whose name started wtih an "L", and two sisters, Mary and Ellen. 

I've found a marriage record citation for Rose Donohoe and John David Fitzgerald April 13, 1846 at St. Andrew's. Putting the pieces together, it could be that they had John two years later and gave him his mother's maiden name as his middle name.

Where I'm stumped though, is in Rose's maiden name. According to family history, all of which has been passed down orally, little of which has been verified, Rose's name was Farlan, not Donohoe. 

Any help untangling the Farlan/Donohoe mystery and locating David H. Fitzgerald would be greatly appreciated.

Thank you.

Amy Fitzgerald