kirranel on Family Tree Circles

My Grandfather on my paternal side has become a mystery, my mother knows nothing about his family, let alone my fathers siblings alsoknow nothing.
William Edward Thomas BELL was born in 1884 in Australia (I believe).He married Ethel Ivy Luders in 1916. He died in Waitara, Taranaki NZ in 1968. I am told his father was John Bell and married Jane M. S. Squires. I have a feeling that John Bell was a convict in the UK, shipped out to Australia. My aunty has also told me that William Edward Thomas BELL has a sister called Beatrice, who had a daughter called Joy, that is all she new.

I am hoping someone can help solve this puzzle.