Swallows and Amazons is my favourite children's book series by a country mile, and a million times better than anything Enid Blyton ever wrote (I read dozens of her books as a child). Arthur Ransome wrote the series between 1930 and 1947. I re-read them every few years and still love all the characters. Nancy Blackett leaps off the page. Her given name is Ruth but she hates it and has taken the name Nancy instead, which she thinks is more piratical. Her uncle Jim feels this is fitting as pirates should be ruthless. 
My favourite characters are Dick and Titty, both of whom would be re-named now, I expect. Sigh.
Susan Walker is probably the dullest character, but Ransome makes it abundantly clear in every book that nothing they do would be possible without Susan (or another character, in the books where the Walkers don't feature) taking responsibility for pitching the camp, making a good safe fireplace, buying in food, cooking it, getting everything cleared up afterwards and making sure the rest of the crew(s) get to bed at a reasonable hour, brush their teeth and don't do anything too risky (Susan doesn't always succeed there). It's made clear that some sensible, everyday stuff has to happen - (a) because otherwise adults won't let them go off on their adventures; but (b) also because otherwise everything would fall apart. Life would be too uncomfortable for adventures to happen.
(That latter point was one of the things that annoyed me immensely about the recent film version of Swallows and Amazons. The children are all extremely capable in the books, but in the film they were portrayed as nitwits who lost all their food on the voyage to the island. )
Oh, and one final observation - at least half of the adult characters are women, and resilient, intelligent, capable women at that. Mrs Walker is bringing up five children mostly on her own while her husband pursues his naval career. Mrs Blackett is a widow bringing up two children alone. Mrs Callum accompanies her husband on his archaeological digs and probably helps out, as Agatha Christie did Max Mallowan. Mrs Dixon, Mrs Jackson and Mary Swainson are farmers' wives/daughters, working hard on the farm and running side businesses (taking in holiday guests/dairy). The Great Aunt is one of the most formidable characters in children's literature. Missee Lee inherits the family piracy business from her father and makes a go of it, in the process forgoing her own dream of becoming a Cambridge Classics don. Mrs Barrable is a painter.