"I'll join you in a minute," she says, her focus still on the screen. He can probably see she's choosing seating assignments now. Before she didn't really care, told them to put her anywhere. Now, though, she is making sure that the three of them are seated together and in the center rows so that Sherlock doesn't feel cramped and panic. She's put him in the aisle seat, then Ted next to him, then herself next to Ted. She figures if Sherlock does get nervous on the flight, Ted will be a lot better at keeping him calm that Joan will be right now. The two of them can also keep each other company, since Joan will likely be terrible company on a flight to her mother's funeral.