Baggott on Family Tree Circles

I am a descendent of Astley Laurie and Te Rangiata who died while giving birth to Annie Laurie in Kawhia. Annie went on the marry William Edwards and then in the next generation, Mary Jane Edwards to Archibald Baggott. They lived in Otago. Archibald's family came from Southland Invercargill.
Astley Laurie was the son of John Laurie who was a convict from UK arriving in Sydney in early 1800's. Astley ran foul of the law in Sydney and absconded to Kawhia. John Laurie married Sarah Bockerah who was born in Sydney in 1792. Sarah's father Solomon Bockerah was a convict arriving on the Second Fleet in 1789. His wife (in UK) Anne was a free woman who also came from London on the Second Fleet following Solomon over. Anne died early in Sydney and Sarah was "adopted" by some friendly people until she married John Laurie. John Laurie died in Karaka south of Auckland.
My lack of understanding revolves around how Annie Laurie and William Edwards, from the North Is, came to give birth to a daughter Mary Jane who ended up in the South Is? Does anybody have anything to add to this story please?
I also have little information as to the background of Te Rangiata who was living in Kawhia?