"I don't think that parents should throw up a white flag and leave the area," she said. "I need to let parents know that there are solutions, and they shouldn't just give up."
She has enlisted some powerful allies.
They include: parents who have done similar work at their own schools; all 12 principals; Lori Shorr, Mayor Nutter's chief education officer; Paul Levy, head of the Center City District, which works to improve the quality of life downtown; and the district itself, which designated assistant superintendent Emmanuel Caulk to help.
The coalition is fighting huge headwinds. It operates in a financially struggling district that has had to lay off school nurses and safety officers. Most of the students are poor. Violence in schools regularly makes headlines.
But there are positive forces at work, too. In the area bounded by Girard, Tasker, and the two rivers, the number of children under 5 has grown 42 percent in the last decade, to 5,287.
Keeping some of those families here could improve property values and boost tax revenue for a cash-strapped city.
Many of the parents in those neighborhoods are highly motivated to help their local public schools. They believe in public education, love living in the city, and know that private school tuition could easily be $20,000 per child.
When William M. Meredith Elementary, one of the 12 coalition schools, faced about $30,000 in budget cuts in 2011, parents collected more than $15,000 in less than a day.
Meredith, at Fifth and Fitzwater Streets, is relatively well off, but the coalition comprises a wide range of schools, from those that are popular with parents to some that don't meet state educational standards.
The coalition schools are: Greenfield, Meredith, Laura W. Waring, Andrew Jackson, George W. Nebinger, Gen. George A. McCall, Bache-Martin, Chester A. Arthur, Edwin M. Stanton, Spring Garden, George Washington, and Gen. Philip Kearny.
The group is pitching its effort as a pilot project and is asking the district for some changes, including more power for principals to modify curriculum and the ability to direct private donations to programs the schools choose. The coalition also wants to avoid red tape by having one district person responsible for all aspects of the plan.
If the pilot is successful, they plan to expand it.
"There needs to be a simplified procedure or process so that people can go directly to the school without getting lost in . . . administration," said Carlson, who works in executive communications.
One of the group's primary goals is to share ideas, business partners, and relationships that have worked at individual schools, said Laureal Robinson, principal of Spring Garden Elementary.
At Spring Garden, for example, a community group is helping to plant trees around the perimeter to make the school more appealing, and Drexel University students and faculty help with science fair projects.
At Jackson, where students speak a total of 14 languages, principal Lisa Ciaranca-Kaplan gets help from Temple University's language department to teach students and parents Spanish and English as a second language.
Teaching parents, too, helps them feel more connected to the school. That serves another major goal of the coalition - to make each school a community center to strengthen the schools and neighborhoods.
"The biggest change has really been community involvement and seeing the neighborhood really embrace the school," said Carol Domb, principal of McCall Elementary, "so if you come into our schoolyard in the morning, you will see hundreds of parents there with their children. They have created their own community."
Bache-Martin, serving the Francisville and Fairmount neighborhoods, is the model for a school as community center. It offers playgroups for young children, which bring parents into the school long before their children enter first grade. On weekends, Bache-Martin is bursting with art, sports, and other classes that neighborhood children can take.
The Fairmount Community Development Corp. obtained the liability insurance required for the weekend programs and pays the district for the costs of keeping the school open after hours.
Already, the Opera Company of Philadelphia, the Clay Studio, and the Vetri Foundation for Children - which aims to help students develop healthy eating habits and good manners - have agreed to work with the coalition.
For Shorr, Nutter's point person on education, the coalition reinforces a movement toward improving local schools. The city recently adopted its own "Great Schools Compact," which aims to set common academic standards among all city schools, including charters. The proposal won the city $100,000 and a chance at millions more from the Bill and Melinda Gates Foundation.
At the Center City District, Levy said grouping schools together could make it easier to raise money from employers.
He cautioned that there was no plan yet and everything was "conceptual." But some aspects of the proposal might appeal to businesses whose employees have children at the schools and that want to set up some sort of matching contributions.
While the coalition coalesces, its members have some advice for parents on the fence about their public schools: Go look at your local school.
Dan Lazar, Greenfield's principal, said many parents walk in hoping to justify sending their children to a private institution instead.
"You can tell they are looking for a reason to rule us out," he said. But many choose Greenfield after a visit. When he started as principal three years ago, enrollment was 473; next year, 543 students are projected.
Carlson recognizes that her plan may be a tough sell in a district with relentless budget cuts. But she is determined.
"You can't let the steamroller roll you over. You can't just give up and leave," she said. "At least, I'm not willing to do that yet."
Contact staff writer Miriam Hill at 215-854-5520, firstname.lastname@example.org, or @miriamhill on Twitter.
Inquirer staff writer Kristen Graham contributed to this article.