Jo ... there is also the possibility of children born to the union of Frank AINSWORTH and Susan Cooper BAXTER.
Please refer to the FREE BMD site for details. 
~ Lu
Hi again Jo
I deliberately left out publishing here the possible English births for AINSWORTH / BAXTER.

I'd think it probable that Frank came to NZ for a new life - he travelled under his birth name, and then re-married here in 1930, so apparently had nothing to hide. And it would seem that he went to the effort of voiding his first marriage in order to marry Ethel Mabel WOODFIELD.
The (1930) "printout" should clarify things for you.
~ Lu