The Force Awakens was centered around Ridley’s Rey and Driver’s Kylo Ren (aka Ben Solo), but the beating heart of the film was Han Solo as he comes to grips with his son falling to the dark side and the ultimate sacrifice he made trying to bring him back to the light.
It was Leia in The Force Awakens who told Han to bring their son home, so it wouldn’t be surprising to see her feel the burden of Han’s death weigh heavily on her shoulders in the next film.
We all know what they decided, towards the climax of the film Han Solo was killed at the hands of his son Kylo Ren with his crossguard lightsaber.
We will also probably see how Han’s death affects Leia and her decisions regarding their renegade son.