In contrast, Vader sensed his connection to Luke Skywalker almost immediately. How did Vader detect his relationship with one of his offspring but not the other? The short answer is that creator George Lucas had no idea Leia would end up becoming Darth Vader's daughter.
Darth Vader only learned he had a daughter in Return of the Jedi - but there's no evidence he realized she was Leia before his death and redemption. Darth Vader may have never known Princess Leia was his daughter in Star Wars and never cultivated a relationship with her, even when he was a Force ghost.
Theory 1: Leia Doesn't Remember Ben Is Obi-Wan
Throughout her encounters with Kenobi in the series, he refers to himself as Ben. The most straightforward explanation would be that Leia knows the person who rescued her is Ben, and never connected the dots that Ben is actually Obi-Wan.
He either didn't realize it was the same protocol droid or figured he'd been memory-wiped so FUNCTIONALLY wasn't the same droid and didn't care.
He did know what Luke was his son, once he knew that Luke's last name was Skywalker. After Vader sensed the strength of the Force in Luke, he spent time trying to find the identity of the young Force-wielder who had destroyed the Death Star.
While their affection had to remain hidden, the two kept in frequent contact, even throughout the Clone Wars. But despite this, Anakin found out that Padme was pregnant only a couple of weeks before the twins were born. So, why did it take so long for her to tell him?
Later, the heroes go to the forest moon of Endor to prepare for a battle with the Empire. There, Luke reveals to Leia that she is his twin sister and that Vader is their father.
Vader agreed to help the handmaiden, silently recalling the time he spent with Padmé in the process. In this moment, he was once again Anakin Skywalker, a young man in love who simply wanted to change the world for the better.
Vader relies on the complex life support system of his suit to survive and it happens to be very vulnerable to electrical discharges. So, if Vader ever had unleashed Force lightning, there's a good chance it would've caused his suit to short circuit, thus, killing him.
Late in the film, Darth Vader does not recognize C-3PO who is in Cloud City with Han Solo, Chewbacca, and Leia. Although C-3PO is not completely assembled in the scene, he is definitely visible to Vader.
Leia does not seem to react to tragedy. Instead, she has this wonderful ability to stay perfectly alert, reasonable, and careful of the feelings of others. She witnessed the destruction of her entire planet, and still had the mental and emotional strength to escape with Luke and Obi-Wan.
She also knows Obi-Wan, and she knows him well. Her holographic plea for help, already iconic, will never be the same. She knows Obi-Wan's real name as well as his alias of “Ben.” When Luke comes barging into her cell and says, “I'm here with Ben Kenobi,” Leia jumps off the bunk in an instant.
Obi-Wan came to the Death Star to save Leia from the Empire's clutches, but was killed by Darth Vader while the others were busy escaping. Leia didn't see Obi-Wan again, nor did she experience any sadness when she learned of his death.
Yes. In the book 'Tatooine Ghost', Leia learns of Anakin's life prior to his evolution into the Darth Vader personae. This revelation leads her to forgive him. She even named her third child in memory of her father.
Reva knows that Anakin Skywalker is Darth Vader because she was one of his targets—a child—during the Order 66 killings that took place during the events of Star Wars Episode III: Revenge of the Sith.
First, she admitted that she didn't really care about the Force. Thus, if she went with Luke, she would be doing it for the sake of being with Luke, not because she was following the will of the Force. However, more importantly, Leia refused to be a Jedi because Darth Vader's power had scared her.
1 Darth Sidious
There has been no Sith, as powerful, meticulous, nor as evil as the Emperor himself, Darth Sidious. As previously mentioned, Sidious trained in the Dark Side by Darth Plagueis before Sidious killed Plagueis in his sleep, making Sidious a Sith Master.
It's likely Kylo never learned how to summon Force Lightning
From what we learned from the Marvel Comics story on Kylo Ren and his upbringing, along with the information explained and even alluded to in the sequel trilogy — it's entirely likely that Kylo never completely learned how to harness Force lightning.
Grandmaster Yoda himself was capable of summoning force lightning in the form of Emerald Lightning. Galen Marek was an extremely skilled user of this Force power, even after his conversion to the light side, rivaling Darth Sidious.
Anakin does not have even the slightest bit of remorse. By the end, he feels nothing but anger. Although he feels regret for killing Padme, he still helps the evil Emperor. The film ends with Anakins standing side by side with the man on whose behalf he has committed all his crimes.
What Padmé knew about Anakin's previous dark deeds. Padmé was well aware that Anakin had committed dark crimes that would've started his fall to the dark side. He even confessed to her that he had massacred an entire Tusken Raider village to avenge his mother, leaving no one alive.
Yes, he remembers everything about his past (just not based on reality), but he probably doesn't spend a lot of time thinking about it, and when he does, his memory of things is clouded and twisted by the lies of the sith, the dark side, and his own flawed thinking and character.
Darth Vader never knew he had twins until that final battle on the second Death Star. The force ghost of Obi Wan had warned Luke to bury his understanding of Leia deep or Vader would be able to sense his feelings.
In Legends, Luke and Leia do eventually discover their mother's identity during the Swarm War Trilogy.