Arnold was Player of the Match in Australia's quarter-final against France on Saturday, making a string of saves late in the game and stopping three penalties in a shootout victory that captured the hearts of the host nation.
"I guess the last couple of days have been a pretty big whirlwind for me," she told reporters on Tuesday.
Arnold also took a penalty in the shootout, pinging Australia's fifth attempt against the post when successfully converting it would have sent them into the semi-finals without the need for sudden death.
Arnold, who has only recently taken over as first-choice keeper for the Matildas, said she would step up and take another spot-kick on Wednesday if called upon.
"I am ready if I have to take one tomorrow, hopefully I don't," the 29-year-old added.
Persons:
Mackenzie Arnold, Arnold, pinging, Tony Gustavsson, Nick Mulvenney, Peter Rutherford
Organizations:
SYDNEY, England, France, Thomson
Locations:
Australia's