Ahsoka has finally arrived and Star Wars fans are excited about the new story with the legendary Star Wars heroes. One of the biggest revelations to come from the initial episodes, and even the trailers, is that Sabine Wren had begun training to become a Jedi with Ahsoka. Despite never showing an aptitude or sensitivity for the Force, Ahsoka took Sabine on as an apprentice, yet the training seemed to fall apart. The first episodes of Ahsoka begin to unravel the mystery of Sabine and Ahsoka's failed apprenticeship and what happened to cause a rift in the relationship.
Source:https://www.cbr.com/star-wars-ahsoka-sabine-explained/