She is the one main character in the present who has known William the longest, and even though he was originally at fault for giving Randall up, it was later Rebecca who made the decision to keep the two apart, which Randall agreed to.
Geez, is somebody cutting onions in here or what?
And while the episode is obviously going to be hard on actors Sterling K. Brown and Ron Cephus Jones, who respectively play Randall and William, but I’d wager that Mandy Moore and her character Rebecca were hit by that plot point in a similarly hard way, and for different reasons.
And, of course, it was a decision she later came to regret, as she saw how much the father and son loved each other and how much of that love was lost over the years due to…