The blue elephant in the room here is ROTJ. In ANH and TESB, the Force was basically space-yoga. It was something that anyone with the correct discipline/attitude etc could learn and perfect - the only caveat being that it was really difficult. It was implied that Luke might follow in his old man’s footsteps and have an aptitude for it, but that’s no crazier than potentially being a great footballer 'cos your Dad was. There was also nothing to suggest that Obi Wan and Yoda had plans for Luke. Obi was in retirement and Yoda seemed to have quit the Jedi business entirely.
ROTJ threw this all out the window by making Luke and Leia a potential threat by birthright alone (necessitated by making Leia the ‘other’ despite no previous Jedi connections whatsoever) and creating that ‘hidden from the Emperor’ nonsense. So now these abilities were inherited. Suddenly Leia was all cosmically aware (“he wasn’t, I can feel it”) purely because she was a Skywalker.
This continues from my previous response to you and affirms my own obsessive nerd qualities.
I am an unrepentant ROTJ apologist and I fancy myself the blue elephant in the room, as you can see from my name.
I see nothing wrong with the idea that Force sensitivity can run in families. That doesn’t mean anyone born into a family will have it nor that anybody else can’t.
Leia could well have been suppressing that part of her psyche because it was at odds with her upbringing or simply uncomfortable for her to admit. Don’t forget that Leia was the one to sense Luke hanging out under Cloud City in ESB. You could say that was all Luke’s doing or recognize it was the first inklings that Leia had latent sensitivity to the Force.
In ROTJ, when Vader referenced the possibility of using turning Leia to the dark side, that was clearly a threatening tactic, not total confidence that Leia would be powerful simply by virtue of her relation.
The idea that anybody could harness the Force if only they tried is far less compelling to me.