The name is not used in Germany at all. I never met one. It seems really nickname-ish and it is very connected to the story so the child might get teased (there's a
German song about Hänsel and
Gretel and all children know it so people might sing that to her). Hänsel is a (very old fashioned and hardly ever used) nickname for
Hans and
Gretel a nickname for
Margarethe.
To be honest I would be really embarrassed to be named
Gretel. It just seems really silly. It is something
German parents would never ever choose, I guess.
Greta, yes but not
Gretel.
Liesel is a very stereotypical
German name as well and I've never met one.
Lisa is very popular, though. You could compare
Gretel to
Gretchen.
Gretchen is also not used in Germany. It was a long long time ago, but also as a nickname for
Margarethe. Do you know "Faust" ?
Gretchen's full name is
Margarethe there as well, it's mentioned in the book.
I never heard of anyone named Gretelise. It looks a bit weird. It would be pronounced GRAY-teh-LEE-zeh. but I never met anyone named that and never saw the name anywhere, did you make it up ?
did you mean to write Greteliese or do you really mean Greteleise ? "leise" is the
German word for "quiet". pr. LY-zeh. so Greteleise would be GRAY-teh-LY-zeh.