Yeah, this was more a process of elimination thing, there don't seem to be many high profile cases coming out of Australia that match that criteria. It could match if she's really, really in denial (possible, given what we're dealing with).Kiesha was beaten to death by her mother and stuffed in a suitcase and the mother is now rotting in prison until at least 2029. Unless this girl is super in denial then it's probably not her.
No idea who else it could be though.
Though there doesn't seem to be too much true crime chatter about it, and New South Wales' age of consent is 16 not 17. So I'd say from further investigation it's possible, just not probable. Maybe some aussie kiwis have some better leads.