The shooting on Monday prompted a lockdown of both the daycare facility and the Catholic all-boys primary school, and parents rushed to the area to pick up their children, the Australian Associated Press reported.
Police said the man and woman who were killed worked together in what he described as financial transaction business.
The identities of the victims and the shooter have been withheld for now, with officials still having to notify their families.
Police declined to comment on whether the suspect killed himself or died some other way, saying it was still under investigation.
Relieved parents hugged their children tight after they were reunited just outside the police tape at the daycare center.
No child was injured, police said.