Greta Gerwig was 21 in LOL when she played the character 'Greta'.
That was over 18 years ago in 2006.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 40, and has starred in 35 movies in total, 34 of those since LOL was released.
In LOL, I think Greta Gerwig looks: