Na, you wouldn't find something like ごとばおじさん in German, since we are not really famous for our sense of humor...
Anyway, two thinks come to mind, though I don't know how well your sister speaks/unterstands German.
1)
"Der Dativ ist dem Genitiv sein Tod" (ISBN-10: 9783462034486): It's a book about German Grammar and the German Language and their notorious missuse by Germans. The book is a collection of articles of a the newspaper column
"Der Zwiebelfisch" (litheral: "onion fish", though it's actually a word from the times when typesetters still put newpaperpages together by hand, but I forgot it's actuall meaning), and the author normaly writes not only about the missuses, but also gives backround information about how they are really used or their history and such. I enjoyed reading the column, but never read the book. Though neither the book nor the newspaper column are written for children, so the language might be a bit difficult.
There are several followup books, but I can't say anything about them, as I stopped following the articles in the newspaper ... hmm, forgot why I stopped reading it actually.
Here ist the English wiki entry about the book:
http://en.wikipedia.org/wiki/Der_Dativ_i...v_sein_Tod
2)
"Die Sendung mit der Maus" (~ the program with the mous), is a kid's program which, next to short catoons and childsongs, also features short films about how things function. So in one episode they might show you how bread is backed, and in the next they explain how a sundial workes. Back in university I used to watch it with my roommate on sundays, and I know lots of other adults who did this or still do this. The short films how things work are really interesting, and frankly it became something like a cult. Though the younger generation might think differen... Tori-Kun?
Well it's just the site of their internet presence, so is
this one, which also leads to the mous-site (6 - 12 years), but also to a site-collection for older kids (10 - 14 years), but I haven't seen their programms, so I can't tell you how interesting/usefull they might be.
Oh, here is the English wiki entry about the program:
http://en.wikipedia.org/wiki/Die_Sendung_mit_der_Maus
Edit: Gahhh, it's late and there are so many typos, sorry about that...
Edited: 2011-03-27, 6:59 pm
