They put up Web ads on Facebook and Allrecipes.com alongside slogans such as “Moms know best: ‘Get yourself health insurance.’ ” They have enlisted the help of parent-activist groups such as Moms Rising, which has already begun mobilizing its vast network of more than 1 million members and 3 million e-mail subscribers on behalf of the health-care law.

They are collaborating with Elle and Cosmopolitan magazines, organizing mom-oriented wine-and-cheese parties and preparing commercials that will run during shows popular with mothers, such as “Good Morning America.” And soon, they plan to deploy first lady Michelle Obama, the nation’s mother in chief, who has already put her stamp on health-care with her anti-obesity “Let’s Move!” campaign.

The targeted messaging is part of an enormous grass-roots campaign mobilizing this summer and fall to persuade uninsured people to sign up for coverage beginning Oct. 1, when systems are expected to be in place for them to find benefits as well as financial assistance from the government, if they qualify.