One of the most emotional moments in The Force Awakens was between Rey and Leia, and a direct result of the most emotional (and devastating) moment of the entire saga. With Rey returning back to the Resistance base after Han's death, the pair share a moment that is a mixture of loss, grief, and also recognition. As far as we know these two have never met, so what's really going on here? Sure, Leia will have heard of Rey and vice versa by this point, but there's more here. This is a moment of two people with the Force recognising each other, and having a deeper understanding than should be possible for two strangers. Of course, the reason could be attributed to the Force and their connections to Han, but it also seems likely to be a subtle nod to a familial connection as well, even if they don't 100% know it yet. After all, when Leia finds out she's Luke's sister, she says that in some way she's always known, and this is something similar: an aunt recognising her niece? But yeah, still could've given Chewbacca a hug though, eh Leia?