Absolutely! That's what I had in mind, and even the Starks. (Which is interesting considering that Catelyn was raised with a lot of knowledge about politics and running a household, because she was heir to House Tully until Edmure was born—a good portion of her life.)
someone_else
I really love more of the Free Cities getting built out because it seems like it tells us a bit about what to expect in TWOW and ADOS. We see that the Triarchy together has a huge impact on the Dance. The Free Cities in general do, but especially the Triarchy. It really feels like we're getting set up and a glimpse into what's in store later.
The Iron Bank has holds on both House Lannister and Baratheon with those loans. With Varys and Illyrio finally making their plans for Westeros explicit, we're seeing that Pentos will likely have a hand in the politics—along with their own dynamics considering that the Tattered Prince wants to invade. Barristan has also agreed to those terms, and I'm sure that Daenerys won't be too pleased about Illyrio supporting a different Targaryen despite his earlier support of her (which she also doubted right from her first chapter).
And then Tyrion has seen how Volantis hopes that Daenerys will swing by and support the slaves. It wouldn't be surprising if sentiments were similar across the Three Daughters, considering that they also have ratios of more slaves to masters. (Wondering if we could see George pull inspiration from the Haitian Revolution? Obviously not one-to-one but just magpie-ing it.)
It's interesting because I find book!Margaery and show!Margaery to be such different characters in some ways (for example, the poisoned wine feels like something book!Margaery would be in on) but I also think about how George said that show!Marg is basically book!Marg if she were 10 years older.
She's also a great example of what it looks like when a family involves daughters in the family business/politicking, so that they're not left to try and figure stuff out on their own later.
House Arryn is a good one because I think it also stands out as among the first and most prominent of the Andal invasion, which was a defining moment. The Andal invasion changed the culture of Westeros and splits up the landmass. It's also a place that during the modern era has a mix of First Men and Andal people living there, showing again the Andal influence and shift of power.
I'd also then put House Martell as another one of the most influential houses, considering how much the Rhoynar migration changed the culture of Dorne and the politics of Westeros.
Honestly, no idea if she did! I get the sense Catelyn might have just because of how Hoster was as a father, and that he seems more ambitious than Ned. I wouldn't be surprised if Ned wanted to shield his children more from the politics or rest of Westeros as much as he could due to his trauma.
I'm not super sure if George thought everything through but things get more fleshed out as he writes worldbuilding stuff (that's not uh TWOW). Like, I think if anything the isolation of the Stark girls and Cersei are exceptions rather than what should have been or what's politically advantageous. The Reach does well in cultivating alliances by having a women's court of a sort around Margaery. We see that for Rhaena (first one) and Alysanne, as well, and it seems like something Alyssa made sure they had from a young age. But this could also be due to George's gardening.