A member of the public discovered her body lying on the beach at 6.20am the next day.
Crombie's name was released today.
It is understood her family farewelled her at a funeral yesterday.
The Herald spoke with Crombie's father soon after she died.
He said the family did not want to speak publicly about what had happened.
A post mortem examination was completed and Crombie's death has been referred to the Coroner.
As such, no further information about the circumstances can be released until the Coroner formally rules on her cause of death.
Police said Crombie had consumed alcohol before she went swimming, but it was unclear if that had any part to play in her death.
Last month, Mangawhai locals told the Herald they were shocked and saddened by the death.
"It's very tragic," said one man who knew Crombie's parents.
After Crombie's body was removed from the beach a karakia was held and a rahui was then placed on the estuary for several days.
Local charter company director Stef Railey said the estuary was a popular spot for swimming but was dangerous for those who were uninitiated.
"People swim in the harbour and there is quite a strong flow, and some big tides at the moment. It's a trap for new players," he said. "They get out there and can't come back in."
People swam right across the estuary and people frequently used the current to carry them so they didn't have to swim. The current was about 3 knots strong.
