Emma Watson was 10 in Harry Potter and the Philosopher's Stone when she played the character 'Hermione Granger'.
That was over 23 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 34, and has starred in 27 movies in total, 25 of those since Harry Potter and the Philosopher's Stone was released.
In Harry Potter and the Philosopher's Stone, I think Emma Watson looks: