Marion Ross

She appeared on Broadway with Jean Stapleton in a revival of "Arsenic and Old Lace" (1987).
In 1972, Marion was hired to play Marion Cunningham in an episode of the comedy series Love, American Style (1969) called "Love and the Happy Days". On the show, she was the mother of a teenager named Richie (played by Ron Howard) and the wife of Howard Cunningham (played by Harold Gould. Two years later, when the segment was developed into a television series called Happy Days - Les jours heureux (1974), Marion was invited back to play her part and so was Howard, while Gould was replaced by Tom Bosley.
When she was starring on Happy Days - Les jours heureux (1974), she and co-star Tom Bosley, who played her on-screen husband, didn't get along, at first, yet, at the series progressed, the two had bonded with each other. Bosley remained friends with Ross, until his passing on October 19, 2010.
At age 13, she changed the spelling of her name from "Marian" to "Marion" because she thought this would look better on a marquee.
She credits her late friend, character actress Sandra Gould, with helping her get the role in Happy Days - Les jours heureux (1974). She was invited to a dinner hosted by Gould and a casting person from "Happy Days" also was in attendance. Not long after the dinner Marion got a call from the studio.

People have different opinions about this, but I'll use it to my advantage. If I call the plumber and he says, "I can't come right away", I'll say, "Did you ever watch Happy Days - Les jours heureux (1974)? I'm Mrs. C, you know". And not only does he get over here right away, but he brings his entire family.
In those days, you would walk into the dining room at Paramount and there were all of these big portraits of all these big movie stars on the wall. Around the corner was Cecil B. DeMille. The dining room was filled with big movie stars. It's all gone now.
[on being the voice of SpongeBob SquarePants’ grandmother] I will meet a little kid who is like 11. I say, ‘Do you know that I am SpongeBob SquarePants’ grandma?' They will turn around shaking all over and show me their SpongeBob underwear. Isn’t that something?