This character hails from a story called "The Black Widow" (D92480), written by Gail Renard and Jack Sutter, and drawn by Jose Colomer Fonts.  It appeared in the U.S. in Uncle $crooge #311.

Scrooge seemed to have twofold motives for his romantic treatment of Mrs. Williams.  On one hand, he was discussing a business deal with her and therefore wanted to keep on her good side.  However, on the other hand, he appeared to be genuinely attracted to her.  He even agreed to a weekend at Mrs. William's country estate. 

Meanwhile, Donald and his nephews suspected that Mrs. Williams was "the black widow", a woman who gets close to rich businessmen shortly before they disappear.  Fearing for Scrooge's safety, the nephews went to Mrs. William's estate. 

At first Scrooge was skeptical, but after a large, nasty-looking spider nearly bit him in his sleep, he realized he was in danger.  Mrs. William's maid, Aggie, offered to help them escape.  She led them into the dungeon, where they were confronted by Williams with an axe.  Frightened, Donald and Scrooge locked her in a closet.  It was then they learned that Aggie was the real villain.  Mrs. Williams broke out of the closet and apprehended Aggie, but was furious with Scrooge for treating her so rudely.

The other missing businessmen were discovered unharmed in the basement.  Scrooge apologized to Mrs. Williams, and they resolved their differences.  Now, however, their relationship was strictly business, and the romance was over.
 
Despite the title Mrs. Williams, she is clearly unattached.  With all the widow references, it can be assumed that her husband is deceased.