I am not sure who she is, but believe she is Countess Marie Berchtold, Baroness von Ungarschitz who married Karl, Count Chotek of Chotkow and Wognin.
From josefnovak33's photostream on flickr; spots removed with Photoshop and sepia tone removed by gogm.
Countess Berchtold wears a half cone crinoline dress plus a hat, scarf tied at the neck, cape, and possibly a lace shawl in this photo by Victor Angerer. She appears to be wearing a wrist watch.
Keywords: Angerer - Victor, Countess Berchtold, Berchtold family, Chotek family, Countess, Austrian, straight coiffure, floral cap, scarf, high enclosing neckline, cape, lace, long close sleeves, cuffs, crinoline, watch, fan