Mrs Rostenkowski is the mother of Bernadette Rostenkowski, as well as several younger children and the mother-in-law of Howard Wolowitz, who is said to be just as motherly over Bernadette as Howard's mother is over him.

She smoked when she was pregnant, resulting in Bernadette's height of only 4'11".

When Bernadette and Howard were discussing their mothers, Bernadette mentions a few things of her mother that drives her crazy:

• Calling her at work or school to find out if she's had a healthy lunch.
• She lays out Bernadette's clothes for her, while not even living with her in the same house.
• Bernadette couldn't ride a bike when she was younger because Mrs. Rostenkowski was afraid she would "hit a bump and lose her virginity".

She ran an illegal daycare center in her basement which Bernadette helped with. Using what she learned she ordered a very tired Sheldon to bed.

She had Bernadette take care of her younger siblings which made Bernadette reluctant to have her own children.

She finally appeared in "The Fish Guts Displacement".  She was a bit scatterbrained, but knew how to get her husband to do things like take Howard on his fishing trip.