Madita is a somewhat less intense Pippi: she has a younger sister and is up to all sorts of ridiculous nonsense, but doesn’t go to society-breaking extremes. Well, usually.
I really admire how Lindgren just manages to make children sound exactly their age, without making them seem stupid or annoying (much). She manages to make their thoughts relatable to anybody, and it’s just magic. The German translation is also, by several accounts, really good, while you should skip the English one.