The bill was introduced again, and passed both chambers of the Legislature. And on Tuesday, Sweeney told Cavallaro early Wednesday, it was finally signed into law.
"It was an amazing moment," Cavallaro said of hearing the news. She also received a congratulatory call from the governor's office.
In February, Cavallaro's crusade looked bleak. Asked at a news conference why he did not sign the original bill, Christie said: "I don't do special legislation to give money to certain school districts."
Sweeney had known he wouldn't sign it, the governor said. Sweeney had called that "bull."
A spokesman for Christie, Kevin Roberts, said Wednesday that legislators passed a large number of bills in January, at the end of their session.
Of those, "many were vetoed because he would not sign bills that could not be properly and thoroughly vetted because of the compressed time frame," Roberts said.
This time, Christie had the opportunity to properly review the legislation, he said.
Cavallaro's district, which added 59 students to its 1,800-student roll this summer alone, will receive an additional $963,615 under the new law.
Most of the districts to benefit immediately are in South Jersey: Burlington County's Chesterfield, Salem County's Elmer, and Gloucester County's East Greenwich, Kingsway Regional, South Harrison, and Swedesboro-Woolwich.
The districts are in once-rural areas that have been gobbled up by development in recent years. The K-6 Swedesboro-Woolwich district had 1,059 students in 2004; 3,200 are projected by 2016-17.
"These districts battling with sharp enrollment hikes need the most help," Assemblywoman Celeste Riley (D., Gloucester-Salem), a teacher and bill sponsor, said in a statement.
Districts' tax revenues are limited by Christie's 2 percent cap on annual increases to their levy. To save money, districts have shared services, eliminated programs, and laid off staff.
That's Cavallaro's next challenge: to lobby for a new state funding formula that can accommodate districts grappling with high growth.
Cavallaro called the new law a "small victory" for the community. At one rally for the bill, 300 people showed up.
On Tuesday, Christie signed several other education bills. One will put a question on ballots in November asking voters to approve $750 million in bonds for capital improvements at colleges and universities. Another allows state and county colleges to enter into partnerships with companies to build campus facilities.
Contact Matt Katz at 609-217-8355 and mkatz@phillynews.com, or follow on Twitter @mattkatz00. Read his blog, "Christie Chronicles," at www.philly.com/ChristieChronicles.