Is Ashoka the other Jedi?
In the video below the theory of Ahsoka and not Leia being the 'other hope', is explored. This theory stems from the original trilogy where Old Ben states that Luke is their(the Jedi's) only hope, and Yoda replies that there is another.
Ben knew of Leia's existence as the prequels show us that he was there when she was born, and given to Bail Organa. Yet in The Empire Strikes Back he seems to have forgotten about her all together. Could it be that instead of Leia, Yoda meant that there was another hope for the Jedi within the galaxy. Could that hope be Ahsoka Tano, thanks the Star Wars Rebels we know that her story did not end during The Clone Wars. The last we saw of Ahsoka was at the end of Rebels Season Two entering the Sith Temple after her duel with Darth Vader. As of now we do not know when we will see her again, but could she play a larger role in the Star Wars cinematic universe, could we see you in the Last Jedi, or will her role remain a mystery.