Does Obi-Wan know.....

He thinks Luke is their only hope because Leia was of no use to them. Her hatred for the emperor and for Vader would have completely undermined Yodas and Ob1's plans from the beginning they would have lost yet another Jedi to the Dark Side. And once the empire and Vader had one of Vader’s offspring in their control it would be too late for the rebellion and any chance of the Jedi making any kind of come back in the galaxy. Leia was weak. Luke was raised basically away from the empire and under the radar of the emperor.

Ob1 knew since the beginning. They kept speaking of the prophecy. The balance that ani was supposed to bring. I have always thought that the prophecy always knew what palpatine and ani would do. I think Luke and Leia are the balance. The civil was going to happen as it does in all cultures. I think Ob1 and Yoda knew about the twins as well as the rest of the Jedi Council. They didn't know or misunderstood the prophecy and realized it way to late. But Vader didn't know about them. Liea was too weak in the force for her to be recognized. Luke was on the one planet that was the furthest away and the one Vader couldn't bring himself to step foot one due to the painful loss of his mother. So Ben and Yoda knew exactly where to hide the twins. Leia followed mommy’s footsteps and Luke followed daddy’s. That is why Ben went so long going unnoticed. Vader was afraid of Tatooine.

Dude we have an official answer to this question. Can a mod close this thread please?

Closing on the request of jedijunky1138.