REUTERS - Ms Jillian Soto was stuck in bumper-to-bumper traffic on a New England highway when she learned over Facebook that her older sister Vicky, a first-grade teacher in Newtown, Connecticut, had died in a shooting.
In the six months since, Ms Soto said she has become an accidental activist for gun control measures, like expanded background checks in gun purchases, and a ban on assault weapons and high capacity magazines.
Ms Soto, who is 24, travels regularly to Washington to meet with lawmakers. Those trips continued even after April, when a background checks bill that enjoyed broad popular support failed in the US Senate.
The defeat was a stinging blow to gun control advocates who had sworn that the public's anger after the Newtown shooting would lead to new laws.
On Thursday, Ms Soto and her younger siblings stood with Senate Majority Leader Harry Reid and other elected officials as the Nevada Democrat vowed to revive a background check bill.
"I think we still have quite a ways to go, but I feel like we are getting somewhere, we are continuing to have the discussion about gun control," Ms Soto said in an interview. "It's just going to take some time."
Before the morning of December 14, when a shooter forced his way into Sandy Hook Elementary School and shot 20 students and six adults, Ms Soto said she knew little about guns. But thinking about sister Vicky's actions that day - hiding her students and intercepting a spray of bullets - had inspired her to work for gun control.
"I remember that my sister died fighting for her kids'safety, fighting for her kids to live. And I will continue to fight like she did, to make sure that nobody else has to go through this pain that my family is enduring," Ms Soto said.
Still, asked what her life has been like over the last six months, Ms Soto used a single word: "hell". Her new experience lobbying lawmakers, while positive in most ways, has been frustrating as well.
"Having Congress people look family members in the eyes who have been effected so badly and say that there's nothing we can do, it's disgusting and they should be ashamed of themselves,"she said.
Ms Soto was on a ski vacation in Vermont with her boyfriend and two other friends when she learned there had been a shooting at her sister's school. They jumped into a car and began making their way back to Connecticut, but encountered heavy traffic.
While thumbing through her Facebook page on her phone, Ms Soto began reading condolence notes about her 27-year-old sister.
"It was by far the worst moment of my life to know that my sister was dead, and my family never even had the opportunity to tell me that," she said. "And I was stuck in bumper-to-bumper traffic when I found out that my sister was dead and there was nothing that I could do." "I remember just knowing that I wanted to do something to get change," she said.
She has been working closely with Newtown Action Alliance and Mayors Against Illegal Guns, a group the New York Mayor Michael Bloomberg helped found and largely funds.
Through her work, Ms Soto said she has grown close with others who lost family members in recent mass shootings, like the 2007 attack at Virginia Tech that killed 32 people. And while those relationships provide comfort, the feeling is bittersweet.
"We are our own group that nobody ever wanted to be a part of," she said.