Well, she is obviously doing it wrong.
You got to mumble "Guten Tag" in no one's actual direction when you enter a waiting room in germany.
Then you don't speak a word (you grab a magazine because if you are on your smartphone people could find that asocial)until the docor calls your name.
When you get back to retrieve your jacket you mumble "Auf Wiedersehen"
If you say "Guten Tag" while sitting down it's either because you are passive-aggressively sharming the person you are talking to for not saying "Guten Tag" or even worse
you are trying to do small talk. (a no go in german waiting rooms) :D