Tess
Yes you are correct that Charles Costello Ferguson is the son of Jane Costello and Hubert Ferguson, and Jane Costello is the sister of my great grand mother Catherine Nolan (nee Costello) and also of William Costello (and Edmond Costello of Gore). When John Nolan married Catherine Costello in Dunedin February 1865, one of the witnesses was Jane Costello of Dunstan.
Jane Costello married Hubert Ferguson in August 1865. Hubert was a goaler in Dunedin, starting in September 1862, later moving to Lyttelton and Wellington. He then became one of the first Factory Inspectors, first in Canterbury, then moving to Auckland in 1892. There are a lot of reports of him in Auckland papers, and he certainly seems to be something of a character. He has an entry in the Cyclopaedia of Auckland, noting he arrived in New Zealand in 1862 on the Black Swan.
Hubert and Jane had a family of eight, two of whom died young - Matilda Jane born 1866 died 1870, Elizabeth Mabel born 1868 died 1935 married Ernest Alfred Le Cren lived in Auckland and Wellington - two sons, Kate Ferguson born 1862 died 1926 married Louis Sanderson lived in Wellington - one son, Ellen Leslie born 1871 died 1943 married John Galbraith lived in Christchurch and Dunedin - two sons and a daughter, Jane born 1872 died 1894, Charles Costello born 1874 died 1960 married Mary Sinclair - 3 daughters and a son? - lived in Auckland, Hubert born 1875 died at sea 1892, Maurice William born 1877 died 1953 married Christina Paton - lived in Christchurch, Dunedin, Invercargil.
Jane's parents were Maurice Costello and Jane Day and she was born about 1845 - there are no records of baptisms from 1844 - 1852. There is no record of her moving to New Zealand that I can find. And I have been having trouble finding when she died.
I would be interested if this fits with anything that you have, and am especially interested in any photographs. I am not aware of any contacts between the Ferguson family and the Nolan's from the second generation, although with Jane and Hubert in Dunedin and the John Nolan's in Central Otago, I might have thought that they may have met. And perhaps with John's brother and 2 sisters also in Dunedin, perhaps they met up with Jane - after all they lived close together in Ireland?
Look forward to hearing from you.
Frank Nolan