I guess "Benjamin" -> "Beni", "Daniel" -> "Dani" and so on are diminutives as well. But Gretchen is definitely rare for Germans that are not way past retirement

I guess "Benjamin" -> "Beni", "Daniel" -> "Dani" and so on are diminutives as well. But Gretchen is definitely rare for Germans that are not way past retirement age (might be more common in some regions but still "exotic"). Actually this holds true for many "German" names. East Germany generally has more "English" (and "French") names, e.g. Kevin, Justin, Steve and Jacqueline. Otherwise there seems to be a general trend towards more Nordic names (some jokingly blame it on IKEA: "naming kids after the furniture they were conceived on").