She is also pretty handy in some of the other styles, showing good technique in the freestyle.
"Probably Lauren Boyle and Sophie Pascoe are my favourite swimmers. I like how they are good at all the different styles."
Milla said she hoped to one day be like them and swim for New Zealand.
For now, she is happy staying put in Rotorua under the tutelage of head swimming coach Alastair Johnson.
"He is a really good coach and has taught us a lot about swimming and is always showing us ways to make our styles better."
Johnson said there were a number of strong swimmers in the club and the main focus was to build the depth so the club could produce more elite swimmers such as open-water champion Kane Radford.
"They are really good kids, it's been quite easy to get them fired up."
He said the club was focused on developing its stocks of first-time swimmers.
"Our focus at the moment is to really nurture and develop those younger kids."