Phoebe Tonkin was 20 in Tomorrow, When the War Began when she played the character 'Fiona Maxwell'.
That was over 14 years ago in 2010.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 34, and has starred in 12 movies in total, 7 of those since Tomorrow, When the War Began was released.
In Tomorrow, When the War Began, I think Phoebe Tonkin looks: