When probing Reys mind Kylo realises that Rey is strong with the force. Was does Vader not similarly realise Leia is strong with the force when probing her mind in ANH? In universe answers only please
Kylo used the force (without the aid of a drug) to probe her mind directly and as soon as Rey starts to turn the power around on him she gives away her force potential. Vader used a probe droid that injects a mind altering drug. He did note that her resistance to the mind probe was unusually strong but he didn't attribute it to any Force sensitivity. All she did was try to resist, not try to turn the probe around and use it on him. There doesn't seem to be a canon answer for this and everything else I can think of is not in universe. Such as during ANH George hadn't decided Leia was a Skywalker yet.
I have always seen this idea as one of the plot holes created after GL decided to make Leia a Skywalker. The argument that Vader simply didn't sense the force in her doesn't hold water, once we see later in the film that he senses Luke is strong with the force, who he hadn't met, from another ship no less. I suppose there's always things that can be made up to explain it away, or whatever someone decided to formulate in their own headcanon, but that's just one of those tough ones. @wobbits, I'm as willing as anyone to accept your explanation however...That works for me.
I'm not saying it's official, it's just how I understood it. I do think Vader should have been able to sense it in her, especially after watching the rest of the OT and the PT but I get George's last minute changes.
Rey has been awakened in the Force by that point, she's definitely pinging on the Force radar (as Snoke and Kylo sense). Leia is just Leia and doesn't know she has that ability. Everyone is a part of the Force but she's not tapping into it at that point. Probably the 1st Force moment she has (that we see) is her connecting with Luke at Bespin, which was years later. It could be her considerable resistance to the mind probe is some latent, unconscious Force ability but not enough for Vader to sense it properly. Same with Leia's force pull to the Raddius (or her making a million to one shot that sinks the bad guys in the Bloodline novel). She seems to have a pretty big "in case of emergency, break glass" Force powers.
You could say that Anakin never learned to be intuitive about the force with others in that way. He only perceives their strength in battle. Also "Your focus determines your reality." The daughter of a senator is hardly an unassuming figure. Would Vader consider her to be anything other than just another hopeless rebel? Would he not just be concerned with the plans and the location of the rebel base? Even those that aren't strong with the force have some resistance to mind probing, it is said. You must remember that Rey actually found a way to push back and expose Kylo's innermost fears.
Leia had never been trained in using the Force, at the time of her interrogation she didn't even have a clue that she had any Force potential. Both Luke and Rey had some small training or exposure to Force powers when their abilities were sensed by Vader and Kylo. The Force had been awakened in them, but not in Leia.
