Leia, not Rey was the most powerful?

Leia is very strong in the Force.

She used the Force in The Empire Strikes Back to mind-link with Luke, sense where he was, and order the Falcon return to Cloud City to retrieve him.

As of Return of the Jedi, Leia was not so sure: "You have a power I don't understand and could never have."

Luke famously revealed to her, "The Force is strong in my family...," but Leia, at that point, was completely committed to the Rebellion and had been since before A New Hope.

One thing I think makes for a very powerful observation is:

The Rebellion was successful in great part that two Skywalkers were on the Light Side of the battle.

Vader and the Emperor only knew of Luke as of Episode V and VI.

They knew of Leia as an Organa, a part of the Rebellion, but not much more than that.

Nevertheless, I believe Leia, just like others not traditionally considered as full "Force-sensitives" (such as perhaps Han flying through the asteroid field), could and did tap into the Force subconsciously and was guided partly by it, very much in the sense of how Obi-Wan explained the Force to Luke when they first met.

Had Luke fallen to the Dark Side or failed in some fatal manner, perhaps Obi-Wan and/or Yoda would have then appeared and appealed to Leia as their "other" Hope.

Outside the films, Yoda is suggested to have preferred Leia over Luke as a possible padawan:

See this story summary from Wookieepedia which references the recently published From a Certain Point of View:

http://starwars.wikia.com/wiki/There_is_Another

 

Okay, I'm not a fan of the whole Leia Poppins part. I would not have minded had Leia been introduced as a Jedi in TFA, lightsaber on hip and all. So it's no dislike of Leia as a character, or based on her gender or any perceived lack of ability she could have had in the ST. I think the book was wide open on Leia and JJ chose not to have her go down the Jedi path. Fine, no problem. Then we have TLJ and her bridge get shot up and her forcefully exploded into space. Again, had she been conscious, I could have probably suspended my disbelief enough to swallow she force pulls herself to the ship. I'd be able to compare that to Luke's moment on Hoth dangling from his feet. I mean, Leia could have had some teachings from Luke and she could have figured some things out on her own over the 30 years or so.

My issue was that Luke had time to get a basic understanding of his surroundings and the danger he was in dangling from the Wampa's ceiling. He had that time, Leia did not. Unconscious, in space, super freezing temps and explosive decompression, not being able to breathe, not knowing where she is (have any of you ever been knocked out?), her age (Luke was in his prime...Leia is not), no apparent training and quite possibly a willful desire to not want to learn the ways of the Force. Then it was done badly, no airlock, no blue light showing some sort of field keeping the atmosphere in the ship when they "rescue" her, just bad decision on the whole thinking imo.

All that said, I think Leia's potential is not greater than Rey's. Luke nor Leia are chosen by the Force, they are offspring from one who was Chosen (unless I read or hear otherwise, I'm guessing offspring have less than the Chosen themselves). Maybe the Force intended that as part of Anakin's prophecy, but we don't know that. I can see Leia and Luke possibly having had close to equal potential to Rey, Rey should be on a level as Anakin (if all we're told so far isn't some sort of elaborate misdirect). Luke lived up to his potential, Leia rejected it and instead of learning how to play Tennis, decided to learn how to play chess. Rey, despite her advanced age (in Jedi training terms) is embracing the Force once the opportunity is given her. Leia still has more training than Rey even if she always fought against it, simply by watching Luke and what he could do. Simply by having 30 years of knowing she could do some freaky space magic.

So no, Rey is superior to Leia, at least in terms of raw power. Leia has just been exposed to the Force more and has a better idea of what it can do. Rey is an anomaly in that she's doing what she's doing with little knowledge, certainly no first hand experience (unless they do some exposition there) of what the force can do. What Leia did was distracting enough to make me unable to suspend my disbelief, but I think it's more of a directors want to make things look cool than an impossibility. It was badly executed and RJ took a few liberties, but I think he could have done something similar without having to try so hard to make Leia look epic.

 

Everything gets handed 2 Rey with little 2 no effort. Luke meanwhile struggled 4 anything.