Julianne Hough was 12 in Harry Potter and the Philosopher's Stone when she played the character 'Hogwarts Schoolgirl (uncredited)'.
That was over 22 years ago in 2001.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 35, and has starred in 24 movies in total, 23 of those since Harry Potter and the Philosopher's Stone was released.
In Harry Potter and the Philosopher's Stone, I think Julianne Hough looks: