After graduating from William & Mary, Margetta started working as an editor at a successful and well-known marketing research firm in New York City, Stuart, Dougall & Associates. There, she met her future husband Joseph Bernard Doyle (1921-2012) who was employed as a Junior associate. They were engaged in 1947 and married in Acapulco, Mexico, in 1948 when he was twenty-seven and she was twenty-three. Margetta worked at the firm until 1953 when their first daughter, Kathryn, was born. Later they had another daughter named Lauren. In a 2006 interview, Margetta noted that it was customary for women to work until they had their first child and not to return until they were grown, and she did just that. She prided herself on being an intelligent confidant and advisor to Joe as he advanced in his career, which ultimately took the family to Canada in 1958 where they have since stayed.

Margetta remembered her father fondly as an avid record keeper who kept diaries of his own, and from a young age she would get blank journals as gifts as his way of encouraging her to record her life as well. Margetta always kept a diary, both before and after her time at William & Mary, maintaining the practice well into her adulthood. She told her interviewer, “I’m not as gushy as I was back then, nor quite as naïve. I think in those days I was very conscious that it was a record I was keeping. And I was pretty careful. There isn’t much juicy gossip in there. Also, I wouldn’t have been surprised if my mother has read it at home—not in a sneaky way but more like ‘Oh, what were you doing last June, dear?’ It wasn’t unburdening my soul as much as— it’s a little more personal now.”