Yeah, that was definitely not the best moment for her. Like, she's seriously one of my top five favorite characters, but I just had to shake my head at that.
Outside of that, though, I think she's definitely learned a lot over the past couple seasons, but at least part of what she's learned is that she can't let on how much she's learning. There's a certain value in being underestimated, and I think Sansa's shown that she knows how to take advantage of that. So, instead of trying to correct people or prove them wrong when they say she's stupid, she uses it against them.