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.