It has been sometime since I read AGoT but didn't Ned get angry when he saw Sansa observing the court when he was holding it? I think he was talking to the Brotherhood.
“From his vantage point atop the throne, he could see men slipping out the door at the far end of the hall. Hares going to ground, he supposed … or rats off to nibble the queen’s cheese. He caught a glimpse of Septa Mordane in the gallery, with his daughter Sansa beside her. Ned felt a flash of anger; this was no place for a girl. But the septa could not have known that today’s court would be anything but the usual tedious business of hearing petitions, settling disputes between rival holdfasts, and adjudicating the placement of boundary stones.” — A Game of Thrones, Chapter 43
You’re right! I wish we had some follow-up on this. It’s kind of ironic, isn’t it? Bran was seven and Ned was like, “Come and watch me execute this dude.” Sansa’s eleven, “This audience hall filled with scared, beaten villagers whom we’re responsible for detailing their destruction of their homes and families, likely on the orders of the family I’m marrying you into, seeking legal recourse, nothing for you to see!” We know he went out of his way to have the boys observe him ruling. The second things turn violent, though, it’s “no place” for Sansa… Even though, as future queen, she’ll likely be handling and/or observing these situations.
I mean, I get that this audience was particularly violent/graphic and Ned doesn’t have a problem with her observing other court sessions but… well… decapitation and also, she’s still going to be exposed to this. At least this way she’s being shown how to handle such a situation. It’s every bit as violent and educational as what Bran witnessed.
Still, it’s nice to see that Septa Mordane was doing her job for once.