Ronja

This name is a Russian pet form of either Veronica or Roxana. Lindgren didn't invent this name. It was used in another book way before Lindgren first released her book.

This is the Russian pet form of Veronica.

This name was NOT invented by Astrid Lindgren, she probably thought she invented it, but it appeared in a book long before her book was released, so it may not be a Swedish name, it is probably a Russian short form of Veronica, meaning "one who brings victory".

She invented it in the sense that she took it from the lake name and it was not an existing name in Sweden before the book, but is now a very popular name. That it appears elsewhere does not change that.

Sure it does. You can´t invent something that already existed! It is a Russian short form of Veronica, that even appeared in a book before having been used by Astrid Lindgren.

But Astrid Lindgren invented it in Sweden. And 12 years after the book released the name got a nameday. So in Sweden she invented it.

I searched a bit in the internet and found out more about the name to make sure that it was not invented by Lindgren. It appeared in a book named "The Candlesticks and the Cross" by Ruth Freeman Solomon which was published in 1967 (Lindgren´s book was published in the late 70´s or early 80´s). The story is set in Russia and Ronja is the name of a Russian character which makes it more obvious that it really is a Russian short form of Veronica meaning "one who brings victory". It could also be a feminine form of Ronald or a variation on the Hebrew name Ronia which means "my joy". Whatever meaning it is the name is definitely not made up but one with a real meaning.