She joins 16 others in the New Zealand world champion squad and goes in with peerless form.
Last month, she won the New Zealand open and under-19 ironwoman titles and went within metres of repeating that double at the Australian championships last week, winning the under-19 title and finishing second in the open.
Halligan had the unprecedented honour of claiming the overall top female athlete title at both national championships, within a fortnight of each other.
She also starred at February's surf league in Mount Maunganui, having linked with the Midway club in Gisborne last year.
"I had an absolute ball when I was back in New Zealand and I'm going to be looking for more excuses to come back and race there."
The former New South Wales age-group netballer, who has recently moved to Brisbane to study, has received unwavering support from her parents, Daryl and Linda.
"Mum and Dad are pretty proud and would've supported me whoever I made myself available for, though I think they're secretly even more pleased it was New Zealand."