She never appeared on the show but....
Well, Just who the heck is Mrs. Olson anyway?

Virginia Christine
aka: Mrs. Olson

Biography:

Virginia Christine
In real life she was a fine, prolific character actress, but Virginia Christine will be remembered for as long as dreams brew near the idiot box for her role as "Mrs. Olson," the coffee swilling matron whose fine black grinds saved many a television marriage.
For 21 years, the wise, matronly Mrs. Olson, with her braided blond tresses and Swedish accent, slipped kindly into kitchens to patch up couples' rifts over bad coffee. Just use "Mountain Grown" Folger's, she advised, and the husband would always stay for a second cup. Maybe it would sober the old goat up. Why the embittered couples didn't pick up a broom and swat the old biddy a few times at this point was never clear. It is common knowledge that one of the most perilous places any cop can interpose himself is in a "domestic."

"As Mrs. Olson I had a wardrobe of aprons the likes of which I'd never seen," she told The Times in 1985 after the commercials had run their course. "She started out as a nice cleaning lady, but thankfully over the years, and after hundreds of commercials, she came of age. She traded in her polyester J.C. Penney outfits for knit suits, and like Cinderella, Mrs. Olson was finally invited to parties, if not balls."
In later years she had a torrid romance with that notorious Colombian rake, Juan Valdez.
Christine's caffeinated role was appropriated by the saltier Taster's Choice couple, whose series is now seemingly also in abeyance. This espresso fad has ruined everything.
Christine was born to two musicians in Stanton, Iowa, a small town that later converted its water tower to look like a coffee pot in honor of her Folger's fame.

Acting Appearances:
She made her motion picture debut in the 1943 film "Edge of Darkness" starring Errol Flynn and set in World War II Norway. She played a peasant girl named Miss Olson. One of Hollywood's busiest performers, Christine appeared in over 400 films, including "Mission to Moscow," "Cyrano de Bergerac," "High Noon," "Judgment in Nuremberg," "Four for Texas" and "A Rage to Live."
She also found parts in cult films, including "Invasion of the Body Snatchers" and "The Mummy's Curse."