Leia’s force sensitivity was pivotal to the development of the plot lines and lore of the now disavowed Expanded Universe. She was just as strong in the force as Luke (as you’d suspect these twins would be because of their distinct bond and infamous father), and her skills as a politician and negotiator were enhanced by this advantage. There was nothing and no one in the galaxy she could not detect, except the Yuuzhan Vong, acting as Heimdall when it came to her children Jacen, Jaina (also twins) and Anakin. Because of her sixth sense, she knew everything, and the Star Wars followers respected her because she was true to her roots and trained as a Jedi, even designing her own lightsaber!
Instead of paying full homage to the EU, Disney decided to downplay Leia’s abilities. Her feminine intuition and maternal strength were heightened by her training as a Jedi, a new breed of Princess that could have reinforced the girl power movement her character started way before she realized Luke was her brother. Back then, the writers proved that force sensitivity, untrained, could miss filial and fraternal bonds. This caveat may explain why the General’s abilities have been stripped down, written to avoid disclosing that more than one person in Episode VIII knows who’s Rey’s family. The Last [Trained] Jedi may not recognize either who she is or who her parents are until her own force sensitivity and true potential are revealed.
Depending on how the movie arc plays out, and how they make Carrie Fisher take her stage right exit -her character’s departure from the franchise was revealed by Disney soon after her death in 2016- we may see if the writers are going to stun us and explain that Leia knew all along who she was but toned down her enthusiasm to not give the story away. Since this movie is comparable to Empire Strikes Back, it is not unreasonable to expect this, as well as other parallels. Luke and Leia didn’t know they were siblings, and Vader didn’t really know they were his twins until he realized Obi Wan was behind the kids’ adventures. No one knew they were related until someone else interjected and pointed it out to them. Rey and Kylo are no different and may be doomed to repeat their fanily history.
It all comes down now to what General Leia Organa Solo has to say when she confronts them during the pivotal scenes in The Last Jedi, and on what Luke spills during Rey’s training. Until then, all we can do is speculate on whether the writers and producers are aiming to blow our fragile little minds or if they missed an opportunity to outsmart us using the force’s sentience inconsistencies. My hope is that Rey and Kylo are actually related or even swapped at birth. There is a chance Kylo wasn’t really Han and Leia’s, and was misdirected to protect his real family. I’d be okay with this twist or with any arcs that make their legitimate heir. (Identities may have been changed to protect the innocence.)
May the force be with us all come Dec 15th. Time will prove us all right or wrong.