The thing about fourth-graders is . . .

They may pull away their hand at school drop-off, but then at home ask if they can crawl into your bed to cuddle.

They may beg you to buy them their own phone, but also find happiness in getting new Squishmallows.

They may amaze you with their knowledge of science or the human condition one day and then later say something that reveals they still believe in the Tooth Fairy or Santa Claus.

Fourth-graders are old enough to present reasoned arguments and young enough to wear cartoons on their pyjamas.

Fourth-graders still get excited about Happy Meals even as their appetites outgrow those kid-size portions.

Fourth-graders, unlike babies, do not leave you wondering who they might become; they offer constant glimpses.

“If given the opportunity, Lexi would have made a positive change in this world,” Kimberly Rubio said last week during emotional testimony about her daughter, who was one of the children killed by a gunman who terrorised two fourth-grade classrooms in Uvalde, Texas, killing 19 students and two teachers. “She wanted to attend St Mary’s University in San Antonio, Texas, on a softball scholarship. She wanted to major in maths and go on to attend law school. That opportunity was taken from her. She was taken from us.”

Rubio spoke to members of the House Oversight and Reform Committee as her husband sat next to her, and at one point, she acknowledged parents who were watching.

“Somewhere out there,” she said, “there’s a mom listening to our testimony, thinking, ‘I can’t even imagine their pain,’ not knowing that our reality will one day be hers unless we act now.”

I am a mother of a fourth-grader and a second-grader, and she’s right — I can’t imagine her pain. But I have spent the days since the Uvalde shooting knowing her reality could easily be mine. Many parents I know have. We have been wrapping our arms around our kids tighter. We have been dropping them off at school and feeling uneasy at the sight of police cars that are suddenly parked outside. We have talked to them about what happened in Texas, trying to divulge brutal facts in gentle ways, before they find out elsewhere.

Recently, my family were walking along the National Mall when we came to a display of flowers representing lives cut short by gun violence in the country. I started to lead my sons past it quickly, but they pulled me towards it, and I let them. Between them and the Washington Monument stood more than 45,000 flowers, creating a visual reminder of the number of Americans who die annually from gun violence. I later talked to my sons about what they saw and realised the only truthful assurance I could offer them was this: there are people right now who are trying to reduce that number.

On Saturday, thousands of people gathered in DC to march in support of ending gun violence. The event, which was put together by leaders of March for Our Lives, the organisation founded by student survivors of the 2018 mass shooting at a high school in Parkland, Florida, comes weeks after the Uvalde school shooting and the Buffalo grocery store shooting that left ten dead.

“This time will be different,” March for Our Lives leader David Hogg, who was 17 when a gunman killed 14 of his fellow students and three staff members, tweeted the day after the Uvalde shooting and again, in a slightly different form, on Friday in response to Fox News publishing his op-ed.

This time needs to be different. This time, gun owners have to be part of the solution. This time, Republicans and Democrats have to agree our fight is not against one another but against those who would abuse our gun laws to slaughter the people we care about. This time, we have to demand more of our lawmakers than lazy soundbites.

This time needs to be different because we know too well what will happen if it’s not. Surrounding that march, throughout Washington, are plenty of reminders of that: murals of the lost. Grief-gutted parents. Traumatised children. People paralysed by bullets. And constant threats of school violence; some that make the news and many that don’t.

RuQuan Brown, a 20-year-old Harvard University student who attended Benjamin Banneker Academic High in DC, was among the scheduled speakers for the march. He has been personally affected by gun violence. It took from him a football team-mate in 2017 and his stepfather in 2018.

“We, in this city, experience this bologna every day," Brown said of Washington residents.

“Do you feel safe?” I asked him.

“Hell no,” he said. “Hell no. Not in DC. Not really anywhere.”

Brown said he planned to speak about “love” at the march.

“The truth of the matter is that it isn’t going to get better until Americans care more about love,” said Brown, who created a non-profit called Love100 and a company called Love1. “Gun violence is a symptom of a broken nation . . . Love is going to address, ‘Why did I pick up this gun?’ Love is going to address, ‘Why have Black people been suffering from violence again and again?’ Love is going to hold and heal people through their brokenness.”

Brown said he believes that this time is different and that people will come together, but he also knows real change often takes time.

“Even after this march,” he said, “I’m still going to be afraid for my life in this country, in my hood and theirs.”

In the days since the Uvalde shooting, schools across the country have experienced a wave of violent threats. One of those threats occurred at my children’s elementary school and directly involved my fourth-grader’s class.

The incident left me concerned, and not just for my kids. It left me concerned for the young person who made the threat and for a country where the threat of gun violence has become an accepted part of childhood.

It also left me thinking about fourth-graders — the ones we’ve lost and the ones we will lose if this time is not different.

• Theresa Vargas is a local columnist for The Washington Post. Before joining the Post, she worked at Newsday in New York. She has degrees from Stanford University and Columbia University School of Journalism