Hi all,
Thanks for your replies, the links, names and suggestions should come in handy! Unfortunately my old phone is playing up and will not let me reply to you individually but the info about Lydia Bowerman, James Whybrow, Benjamin Shadbolt and the Pankhurst Boys etc. is very interesting.
From what I have found, convict ancestry in NZ was, unsurprisingly, often hidden, however I recall finding mention of convicts and their descendants on Papers Past so there was definitely some awareness of their presence here at the time.