By the time of Star Wars: The Clone Wars - first in the animated movie and then later in the animated series, which only recently completed its final season - and continued fighting tyranny in the galaxy well through the Galactic Civil War.
Unlike most of the people she fought alongside, Ahsoka was just a teenager throughout the Clone Wars - she was, after all, a Padawan, just like beat Darth Maul on Mandalore, but it was something that was contested by those who looked down on Jedi leading the Clone Wars.
Ahsoka was 17 years old when the Clone Wars ended and she disappeared shortly after Palpatine enacted Star Wars: Episode III - Revenge of the Sith, that makes Ahsoka 31 years old in season 1.
Since Ahsoka is 31 years old when Star Wars Rebels starts, that means she's 36 years old when it ends - at least when the core story ends in the lead-up to both the Battle of Scarif in Sabine Wren after the Battle of Endor, which was four years after the first Death Star was destroyed. That means, all in all, Ahsoka was 40 years old the last time Star Wars fans saw her on-screen.
Of course, The Mandalorian season 2. Since that show takes place five years after the events of Return of the Jedi, Ahsoka will be 45 years old, unless the new season has a time jump.