I regret to report that Kezia is neither a Maori name nor a name originating in New Zealand. It appears in the Bible — in the form Keziah. If you look for the meaning of the name, you wind up on an Israeli web page where its Hebrew meaning is given as “cinnamon-like bark” or “a daughter of Job.”
Kezia was used in England – where, indeed, it was pronounced to rhyme with the British version of “Maria” (i.e. MaR-EYE-ah). It was brought to New Zealand by settlers – including a certain Kezia Godfrey. Born in London in 1834 Kezia emigrated to South Africa in 1859, after marrying (in a Baptist Church) one Samuel Crawford, shoemaker. Samuel died a year after arriving at the Cape. Kezia traveled to New Zealand in 1864 with her second husband, George Tippett (also a shoemaker).
Almost immediately George drowned when canoeing to get stores for their new homestead. Kezia married for the last time in 1865 – to Robert Baynes (who had hired the widow as his housekeeper). In 1871, Kezia gave birth to a girl, named Kezia. The baby died within her first year. (Several Baynes children did live and carried on the line.) Robert died in 1895, Kezia Baynes in 1902. They are buried next to two dead infants (including, presumably, Baby Kezia) in Waiuku Cemetary. Their farm was in Waipipi.
… So there’s more than one “Kezia story” to be told among the Kiwis.
(As well as elsewhere: a search of “Kezia Massachusetts” brings up many names – including a psychologist in Springfield. And the first wife of Barack Obama Sr. was named Kezia.)
https://www.names.org/n/keziah/about#pronunciation (4 audio clips from American and British voices.)