Stefanie Wiedenroth, 22, died on Monday after her parents had travelled from Germany to be at her side, the Royal Perth Hospital said.
Wiedenroth was on a working holiday at a remote sheep station in Western Australia when lightning hit her on Friday morning as she was walking in a paddock.
Four other people standing nearby were reportedly thrown to the ground but not seriously injured.
Her employer Darren Major said he was standing about 25 metres away from Wiedenroth when she was struck.
"Right above us it was basically blue skies but just off to the west of us there were clouds brewing but nothing to be concerned about - it was basically just a normal day," he told the West Australian newspaper.
"It was just a freak lightning strike, that's the only way I can describe it."
According to the Australian Bureau of Meteorology, between five and ten deaths in the country are caused by lightning each year.