There's multiple storylines in the series, so I'll do one for each protragonist.
Helen: She always carries around a slinky toy and has a tendency to twirl her fur when she’s feeling fidgety.
Shirley: She hates Perogies.
Carol: She maintained a huge victory garden for her family during WWII.
Barbara: When she and Howard got married, she planned on wearing cowboy boots down the aisle. She changed her mind at the last minute.
Irene: She always keeps a butcher’s knife in her nightstand, a habit she refuses to admit she picked up from her husband.