It happened four years ago, but I can still remember how jolted we were by 7-year-old Kayden Mancuso’s death following a years-long custody dispute.

Night after night, local TV stations broadcasted video of Kayden dressed like a beautiful fairy princess in a long, white flower girl dress at a wedding, and dancing at her home in front of a TV to Rachel Platten’s “Fight Song.” We grieved along with her family, asking: How could something like this have happened? What went wrong?

There had been warning signs. Jeffrey Mancuso, 41, had physically abused Kayden’s mother and other family members and made numerous threats. Months before she was killed by her father in a murder-suicide, Kayden expressed her fear of him, which was relayed to family court authorities in Bucks County.

Yet, Mancuso was allowed to have unsupervised visits with his daughter, despite his long history of mental instability and violent outbursts.

Then, on Aug. 6, 2018, Kayden’s stepfather, Brian Sherlock, discovered her tiny, lifeless body with a bag over her head in the living room of a home on the 4500 block of Wilde Street. She had been beaten with a 35-pound dumbbell.

Afterward, Kayden’s mother, Kathryn Sherlock, vowed to do everything possible to prevent the same thing from happening to another child. She appeared a number of times on local stations such as Fox 29 and was interviewed on an ABC News national program just a month after Kayden’s death. I remember marveling at her strength and composure.

She created Kayden’s Korner, a nonprofit in her daughter’s memory, and has organized annual golf outings to raise money for her foundation. (The next one is scheduled for Aug. 1 at LuLu Country Club in Glenside.)

But perhaps most importantly, Sherlock met with Gov. Tom Wolf and pushed for legislation to mandate supervised visitation for parents with a history of violence or abuse. Along the way, she gave birth to two more children, while working full time as an emergency room nurse at Capital Health in Trenton.

» READ MORE: After 7-year-old Kayden Mancuso was killed by her own father a year ago, her mother now fights to protect other children | Jenice Armstrong

Now, four years after losing her daughter, Sherlock’s hard work has come to fruition. On Wednesday, the Yardley resident sat at the White House and watched as President Joe Biden talked about reauthorizing the Violence Against Women Act, which was amended to include Kayden’s Law, which incentives states to improve their child custody laws to better protect at-risk children. “No one — no one — regardless of gender or sexual orientation, should experience abuse. Period,” Biden said that day. “And if they do, they should have the services and support they need to get through it.”

When he was finished, Biden beelined through the crowd to Sherlock and embraced her not once, but twice, and said: “I lost two.” He teared up. She teared up. Onlookers did as well. Afterward, Sherlock went to dinner with actress Angelina Jolie, who was in attendance and has been advocating in favor of Kayden’s Law.

With this signing, a huge chapter of Sherlock’s life has ended.

“We are finally being heard. Congress is saying that this is a problem and we need to do something about it by validating what we’ve been saying and screaming for years,” Sherlock told me Thursday. “We’ve been heard. And we’re not going to stop. We still have a lot of work to do.”

So another chapter has begun.

“Now we basically have to go state by state and get the states to adopt Kayden’s Law,” Sherlock said. “There’s money and incentives and stuff, but it’s not an overnight fix.”

Each state has its own custody statute with different ways of dealing with these issues. The challenge is to get them to update their laws to be more protective of children and make them aware of federal funding that can be utilized. Pennsylvania is ahead of some others. On Wednesday, State Reps. Tina Davis (D., Bucks) and Perry Warren (D., Bucks) called on the Pennsylvania House to pass Kayden’s Law. It was passed by the state Senate last summer.

Danielle Pollack, a policy manager with the National Family Violence Law Center at George Washington University, helped craft the language in the new law. “The thing now is to help states all over the place a) become aware of federal Kayden’s Law and b) to really advise them on the language they might want to consider putting in their state law and help them kind of shepherd it through their state legislatures and get it enacted,” Pollack said.

As for Sherlock, when I caught up with her on Thursday, she was back at work in the emergency room.

“It wasn’t my goal in life to have a law written in my daughter’s name,” she told me. “All I asked from the beginning when I was standing in front of Gov. Wolf’s office [was] ‘Something went wrong here. Let’s see what went wrong and let’s fix it to make sure that this never happens again. It shouldn’t be that hard. This is something that’s preventable. We know the recipe for what happens and why it’s happening and yet we’re doing nothing about it.’”

Thanks to her, we are now.