How? How would you reach that conclusion just by that? Honest question.
I mean the descendants part is quite obvious, but the specific roles? Not saying you're wrong, just how?
Think about it: The family angle in Star Wars. The Skywalker connection to the Force, good and bad. A lost soul with a special connection to the Force who must seek out a master and whom is destined to balance it. It's been a riff played over and over. How else would this play out if you wrote it? It just seems so natural given the context of the storylines from the six movies.