"The lead-up to a tournament like World League 3 will be a crunch point because that's where to take your No 1 side," says O'Hanlon before playing in the opener against Japan yesterday in the Hawke's Bay Cup tourney.
She had been training with the Hockeyroos post-Rio Olympics in the hope that incumbents Rachael Lynch and Ashlee Wells would consider retirement but discovered they had signed up until the end of next year, which will keep them in World Cup frame.
"There wasn't going to be any real opportunity for me after that," she says, looking forward more to preventing the likes of Hockeyroos and mates, such as Madeleine Ratcliffe sneaking in goals past her.
The Paul Gaudoin-coached Aussies have also included development keeper Jocelyn Bartram on their visit to the Bay.
"Jocelyn is fantastic. She's my age so worth establishing in the squad and yet another strong competitor for me over there."
She harbours no regrets in switching allegiances with her dual nationalities.
The great culture of the Kiwis is a fitting endorsement of her decision and she believes she fits in well.
"Not a little - a lot," says O'Hanlon with a chuckle. "I get hassled every single day for the accent but I'm practising really hard and the slang [Kiwi] and other sort of stuff I'm starting to pick it up."
Father Greg O'Hanlon, who she believes "will die inside if he ever jumps the fence" to becoming an Australian citizen, is a New Zealander, and mum Susan, is the Aussie.
"My dad is born and bred in Auckland and he's one of seven brothers and sisters so, in fact, I have more family in New Zealand than I do at home, which is really good with the move in having the whole family here already."
O'Hanlon had flirted with the idea of crossing the floor since 2014, striking a dialogue with Hockey New Zealand but her career in Australia was becoming more defined.
"They put the development work in so I stayed there for two years."
However, it all came to a crunch to pursue her career with no stones left unturned or put it on the backburner to return in the Aussie scene when competition for places was going to cool off.
The ACT Strikers player made her New Zealand debut against Argentina where she played three games.
She is from the same hockey club, Maryborough, as Black Sticks coach since 2008 Hager - a hockey stronghold where she reckons "there's something in the water".
"I've only ever heard good things about Mark as a coach. In Australia he's very well respected and ... er ... feared ... almost," says O'Hanlon, lauding Hager and his stable of support staff here.
"It wasn't like I was moving anywhere that was haphazard or whatever because I knew I was going to get equally as good coaching and players."
She didn't want anyone to influence her decision so she did what was best for her.
"They [parents] supported me. Dad was very excited."
Mum?
"You see, if I'm happy she's happy and if she has to come to New Zealand to watch me play then all the better for her."
Older brother Pat, an engineer, and younger sister, Riley, is studying journalism but neither is into hockey in Maryborough.
She hasn't noticed a gulf or too many differences between the two nations' approach to the code and its development as both bodies' programmes and style of play are similar.
"Over here you train early mornings and late evenings but in Australia you train during the day so we don't have jobs although I studied around hockey."
Having trained with the Hockeyroos, O'Hanlon is familiar with their strengths and weaknesses and is mindful so are they.
"I can probably get in their head a little bit but they also know my strengths and weaknesses so it'll be a really good challenge."