Not with my chapter, BUT girls wearing fraternity greek letters is not uncommon at all.
Basically any girl that serves gets a lettered T-shirt - like I said before, my chapter is not that way, heck until we get our charter we can't even wear the greek letters!
I think the letters thing should be for brothers and engaged girls only.
Pinning to me is a BIG deal....I just hope I pin my girl before I graduate...
Can't wait...