Other Information Sources
Although The Raven Queen is a character in Dungeons and Dragon's, her creation seems to hold ties to many other characters of myth and legend from many cultures. Here is an excellent write up of all the possible roots from which the designers of The Raven Queen could have drawn inspiration.
Story-Games.com has available a map of The Raven Queen's throne room in 7x10in tiles, downloadable as a PDF.
The Raven Queen can also be found in Wizards of the Coasts' supplemental rule books Divine Power and Manual of the Planes.
Currently there does not appear to be a likeness of the Raven Queen in Miniature, however, her arch nemesis Orcus is available. Not sure I'd call him mini though, he is in fact "gargantuan" according to their scale.
If I had to speculate, based on the amount of information that is now available about The Raven Queen, and the obvious interest the D&D community has in her, not to mention the fact that she is Orcus' sworn enemy and goes about stamping out followers of his... I'd have to say smart money is on a Raven Queen Miniature sometime in the near future. One can hope, at least!
I will keep my eyes open, and post a comment if one becomes available. Should I miss it, please let me know in the comments!