Tracy Stettner, 44, of Hillsborough, Calif., said it was difficult to explain to her two children why the younger son’s school — which is private — had suspended in-school classes, to guard against spreading infection, while her older son left every morning, spent the day in close quarters with 1,200 other teenagers, and returned home.

“It needs to be all or nothing, or else how do we stop the spread?” said Ms. Stettler. “The most confusing thing to my kids is, why is the N.B.A. canceling, and Disneyland, but my school is still open? It doesn’t make sense.”

She, too, was eager for a higher level of government to step in — in her case, Gov. Gavin Newsom.

“Our public schools are waiting for him to say something,” she said. “They need him to say, ‘any kid that’s pulled out is an excused absence.’ And even more, they need him to say, ‘no mass gatherings,’” which would trigger the closings of schools.

In Bellevue, Wash., Geng Tan, 48, wondered why her children’s schools remained open, when the schools in the next county over had already closed as a precaution.

Ms. Tan, an architect who grew up in China, concluded that the hesitation was “really related to the American social structure.”

“I think, under special circumstances, we do need a higher level to make dramatic decisions,” she said. “Basically, the school hesitated to make that hard decision themselves.”