The first mention of the wife of Santa Claus is in the 1849 short story "A Christmas Legend" by James Rees. The Philadelphia-based Christian missionary wrote the story about an old man and woman, both carrying a bundle on the back, who are given shelter in a home on Christmas Eve. The next morning, the children of the house find gifts as the couple is revealed to be not "old Santa Claus and his wife", but the hosts' long-lost elder daughter and her husband in disguise.

Over the next few decades Mrs. Claus appeared in a number of children's books and short stories. In 1889 Mrs. Claus makes her most detailed appearance in the poem "Goody Santa Claus on a Sleigh Ride" by Katharine Lee Bates. It is from this point Mrs. Claus has usually been depicted as a gray haired, heavy set woman, fond of baking cookies and spoiling Santa. She usually has on a red dress, trimmed in fur and wearing a white apron.

Mrs. Claus has made numerous appearances in folk literature, songs and poems. She, along with Santa made their move into movies and eventually onto the small screen in both live action and cartoon forms. One of the most famous Christmas specials is the children's show, "Santa Claus is Coming to Town." This fictionalized account tell how Kris Kringle became Santa. The town school teacher, named Jessica, falls in love with Kris and they end up getting married. From then on "Jessica" becomes Mrs. Claus. No holiday season would be complete without watching this classic cartoon.

More Info: en.wikipedia.org