So while looking around for a new Shermie avatar, I found a couple of interesting pictures.
The first is this:
This might have originated on a DeviantArt account by a non-SNK associated pixel artist at
http://armentis.deviantart.com/ but his page is in Spanish so I can't read the info.
The second is more promising:
This was posted on DreamCancel's Facebook in May but there wasn't much discussion of it. I did a search on the forums and didn't see any discussion either. To me this looks like a legit sprite and very much in line with 13's presentation/art. I can't find out where the image came from but I remember someone posting a link from SNK that detailed their sprite creation process and I have to admit this looks like a finalized version of that process.
As a Shermie lover this has got me pretty excited. I'm hoping it's real and maybe in the future we'll see her as a DLC or in KOF 14!