Who is the "her" Tess and Randall are going to see?
OK, so it's clear from the season two finale that Tess and Randall are dreading going to see "her." Originally, this led some fans to speculate that something happens to Beth, Deja, or Annie. Tess specifically tells her father that she's "not ready" to face seeing whoever this person is. Now this could be because the "her" in question is sick or dying, or because she did something to hurt the Pearson family.
In a recent interview with The Wrap, actor Sterling K. Brown explained that Randall is seeking out his family members, and Tess, in particular, to go see this person. He explained, "There's a reason why he had to seek out Tess in particular. Yes, there's a reason why he had to seek out Tess in particular, because Tess hadn't seen the 'her' for some time. And so there's a reason why its time to go and she's like, 'I can't.' There's a reason. Other people may have been more easily galvanized, but Tess needed a little more coaxing."
And yes, the person concerns Toby, as well, even though he's no longer wearing his wedding ring. But that doesn't necessarily mean that the "her" is Kate, or even a single person.