Taylor Swift was 17 in Taylor Swift & Def Leppard - CMT Crossroads when she played the character 'vocals'.
That was over 16 years ago in 2008.
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 28 movies in total, 26 of those since Taylor Swift & Def Leppard - CMT Crossroads was released.
In Taylor Swift & Def Leppard - CMT Crossroads, I think Taylor Swift looks: