The boy's mother, Anastasia Kim, said that had it not been for McCall, "I could have a dead child on my hands, quite honestly."
McCall's annual pay after accounting for health insurance deductions? About $28,000. And not nearly enough, in her estimation, for the responsibilities that she and others in her position must shoulder.
Concerns about teacher pay are nothing new. But there's an emerging battlefront over schoolhouse salaries, and it involves compensation for the employees who play supporting roles in schools — the teaching assistants, bookkeepers, bus drivers and custodians who shepherd students to class, care for them in classrooms and clean up after them.
"I don't think people realize how important our job is and, I hate to sound dramatic, but if a student does have anaphylaxis and does die, where's the responsibility? It's with us," said McCall, who has worked at Lovettsville for 14 years, tending to skinned knees and sour stomachs, and managing students' inhalers and their allergies.
"It's just really degrading to feel like you're not appreciated," she said.
In Loudoun County and other wealthy suburbs, some of those employees, including McCall, have to work second or third jobs. And even then, they can't afford to live in the communities they serve because of high housing costs.
Loudoun schools are moving to address lagging pay, with increases proposed for next year. But employees and educators say that's insufficient.
"If these people are important enough to work for our kids, why aren't they important enough to be paid a living wage?" said David Palanzi, president of the Loudoun Education Association, a local federation of school employees.
The district is reviewing wages for all positions — including support staff members, who are known as classified employees — district spokesman Wayde Byard said in an email.
"Classified employees are an important part of supporting [Loudoun] students," he wrote. "Last year, [Loudoun] began taking several coordinated steps to continually review and adjust pay for these valuable employees."
An online questionnaire circulated to support staff by the union returned stories of workers beset by money woes.
From a cafeteria monitor: "Being a monitor and bus driver you live very poor where you can barely make it."
From a job coach: "I bring home $568 every two weeks. That is poverty level."
From a behavior assistant, who wrote that his wife is a fourth-grade teacher: "We cannot afford to live in Loudoun County and we live paycheck to paycheck. We had $0.56 in our account for 2 days before payday. We have 2 kids, live 45 miles away, and still cannot live comfortably."
Loudoun's superintendent, Eric Williams, is proposing an average 3.7 percent raise for support staff for the next school year.
Some support workers were already given pay adjustments this year. For bus drivers and technology assistants, those adjustments resulted in an average hourly boost of 6.8 and 14 percent, respectively, according to the district.
The starting pay for a bus driver in Loudoun, about $28,284 a year, is now among the highest in the region, according to the union. The starting pay for a technology assistant rose to $23,151, but Palanzi noted that the district also added responsibilities to the role.
He said the increases aren't enough. Rising health insurance costs mean that more money will probably be deducted from paychecks. And a pay raise of a few percentage points doesn't add up to much for workers with low hourly wages, he said.
"They're not making up any ground at all," Palanzi said.
When Karen Tyrrell, a technology assistant at Belmont Ridge Middle School, started in Loudoun schools more than a dozen years ago, support positions tended to be filled by people looking for a second job that would help pay for summer vacations and other extras.
Over time, the paychecks became indispensable. "With the cost of living in Loudoun County and just the cost of living in general . . . it's become a necessary and expected income," Tyrrell said.
Employees in school districts across the region have encountered similar struggles. Riley O'Casey, president of the Prince William Education Association, said workers there often live with roommates or take second or third jobs.
"We need to make sure that our employees are respected, and part of that includes a salary that lets them live," O'Casey said.
In Arlington County, a 2017 compensation study found that pay for some support staff significantly lagged other school systems. Increases are planned over three years for certain positions, including custodians and bus drivers, said Kristi Murphy, the district's assistant superintendent of human resources.
The Arlington Education Association, which represents school workers, has long fought for higher wages for support staff, said President Ingrid Gant, a former middle school resource assistant, a role in which she co-taught classes. Gant moved to Woodbridge 15 years ago after finding that she couldn't afford to buy a house or rent an apartment in Arlington.
Gant said she knows few educators who teach or work in Arlington schools and live in the county — for the same reasons she can't. Many juggle multiple jobs, she said, and some commute from Stafford County or Fredericksburg.
"I'm a born-and-raised Arlingtonian," she said. "Never thought I'd be a commuter, but I could never afford to live in Arlington based on what I was making."
By dim lamplight inside the brick rambler she and her husband occupy in Lovettsville, McCall, the health clinic specialist, fiddled on a laptop as she prepared for her shift as a hospice nurse — her second job.
It's past 3 p.m. on a Wednesday and, after arriving home from her job at the elementary school less than half an hour earlier, she has changed out of a colorful scrub top festooned with hearts and flowers and into a navy blue version.
McCall's husband had back surgery last year, she said, keeping him from taking on construction jobs and further straining the family budget. They were considering selling their home when the job as a hospice nurse came along in June.
It has been a lifeline. McCall clocks three five-hour shifts on weekdays and a pair of 12-hour shifts on the weekend. The additional money isn't enough to maintain a rainy-day fund, but it covers most of the $1,350 monthly mortgage and the electricity, water, car insurance, cable and other bills.
"I'm tired, you know, but I love what I do," she said. "I'm a nurse. I love taking care of people."
For the past seven years, she has worked 50 to 70 hours a week. She's up to 79 hours now.
She counts herself fortunate because she has a nursing license that helps her find a second job. "I feel grateful I have the ability to do it," she said.
Wednesday night's shift started as it normally does. McCall punched the address of her first visit, 47 minutes away in Reston, into her iPhone. She reviewed patient information, jotting notes before closing her laptop and exiting through the kitchen door.
In the driveway, she slid into her Buick, bringing to life the engine as the night began.