I too am descended from Dr Frederick Harpur and his wife nee Elizabeth Finnis. My direct ancestor is their eldest child Sarah Harpur who married into the Evans family. I have found the NSW birth registration of Fanny H Harpur but not bought it because she was not a direct ancestor. I would have expected her middle name to be Hornsby as she has ancestors of that surname.

My biggest query about the family is the suggestion that Frederick Harpur was an illegitimate son of George IV. But who was his mother? I haven't found her.