Angel Carter Conrad isn't the only one keeping her twin brother Aaron Carter's memory close.

Her 5-year-old daughter Harper with husband Corey Conrad "knows Aaron is in heaven, I tell her that," Angel told E! News' Francesca Amiker in an exclusive interview. During a recent drive to school, "she said to me, 'You know, Mommy, I want to tell you something. Aaron, he lives in my heart, and he talks to me in my heart.'"

Angel was grateful to be wearing sunglasses.

"I just started crying," she recalled, "and I didn't want her to see me. But she said that: 'Aaron lives in my heart.'"

It's been almost 18 months since Aaron was found dead in his bathtub at the age of 34, the coroner ruling his death an accidental drowning with the effects of alprazolam (sold as Xanax) and the compressed gas difluoroethane listed as secondary causes. 

And Angel, who as an ambassador for the Kids Mental Health Foundation presided over a Family Celebration Day April 28, is determined to make sure her brother is remembered for more than just his struggles.

"I want Aaron's legacy to be more than the last few years of his life," the 36-year-old explained. "Aaron did have a platform and a love for his fans. And now I would like to see the legacy of Aaron change into something positive, which is to continue to raise awareness, to help children, to save lives."

After the Songs for Tomorrow benefit concert she and Lance Bass hosted last year for mental health awareness in Aaron's honor, a fan of the "I Want Candy" singer got in touch to say a friend was inspired to check into rehab a day after the show.

"I'm just so thankful that Aaron has touched so many people's lives, and will continue to do so," Angel said, "and I hope to be a vessel for that for him."

After he died, "a fire lit inside of me to want to continue the conversation about mental health, and to break this stigma that surrounds it," she said. "Aaron had this fear of talking about his issues for so many years. We always wanted him to get the help that he needed and to have an openness to talk about it."

But while Angel, who married Corey in 2014, has an inspiring handle on her grief—"I always say, I'm better today than yesterday"—she started putting in the work early on to break the cycle of dysfunction and tragedy that has plagued her family.

In 2006, the model starred on E!'s House of Carters with her four siblings, and now she and brother Nick Carter, 44, are the only ones left.

Leslie Carter died of an apparent overdose of prescription medication in 2012 when she was 25 and they just lost their 41-year-old sister Bobbie Jean Carter in December to a toxic combination of fentanyl and methamphetamine. Her death was also ruled an accident.

Mom Jane Schneck and dad Robert Carter, who died in 2017, divorced when she and Aaron were 15 and the family had "split apart," Angel said, noting that just being in the same house with her brothers and sisters was a cherished memory. "It had been years since we had all lived together."

And when filming wrapped, she continued, "Nick set us all down in the living room, and he said to us, 'Who wants to go to therapy? I will pay for you to go to therapy.'"

Angel, 18 at the time, was the only one who took the Backstreet Boys singer up on his offer.

"It really was a defining time for me," she said. "I've been in therapy ever since then, and I'm just so thankful that I took that opportunity and seized it, because in the long run it really did save me."

Angel credits therapy, a healthy lifestyle and surrounding herself with "good people who are educated and want to be better" with her continuing ability to cope when the odds didn't seem to be in her favor.

"There are times where I feel angry over things that have happened," she acknowledged. "But I have such a deep understanding now of the psychology behind my family dynamic and it is so deep-rooted. This is a generational dysfunction issue. And when Aaron died, I said to myself, This stops today. We are not going to live like this anymore. The children of this family are going to not live in this anymore. And we are going to break the cycle."

In addition to Angel and Corey's daughter Harper, the next generation includes Aaron and Melanie Martin's son Prince, 2, Leslie and husband Mike Ashton's daughter Alyssa Jane, 13, and Bobbie Jean's daughter Bella, 8. Nick shares son Odin, 8, and daughters Saoirse, 4, and Pearl, 3, with wife Lauren Kitt Carter.

Prince, who was 11 months old when his dad died, "is a really smart, vibrant little kid," Angel shared. "He has a lot of support from his family and from his mom, and we really hope to teach the kids—in the Carter family and in life in general—that bad things are going to happen and at the end of the day it is a choice to find the good in every situation."

Part of their silver lining is The Recovery Album, a compilation of Aaron's performances due out May 24, with proceeds going to a trust the family set up for Prince, as well as to the Kids Mental Health Foundation.

Angel said she loves being a part of the organization particularly because it focuses on giving children the tools they need to deal with emotional upheaval before it happens.

"We don't call it preventing," she said. "We call it early intervention for a reason, because if you start implementing change and healthy conversations within the home from a young age, and really listening to your children and being there for them—being physically, emotionally, spiritually present for your children—that's all your kids want."

One day, Angel said, when he's the right age she'll tell Prince "the truth, that Aaron was a happy soul and he was a good person."

And she knows her nephew will learn the more upsetting truths about his whole family one day. "That's just a given," she said. "But I hope that he sees how important mental health is, and the vital work that we're doing creating these healthy conversations, and that he sees the lesson in all of this."

Ultimately, Angel added, "I want to show the children in my family—my daughter, my nieces and nephews—that these moments don't have to define you."

Instead they have plenty of happier memories to look back on. Check out some of the family's best moments. 

Nick Carter, Aaron Carter, Bobbie Jean Carter, Leslie Carter and Angel Carter pose for a family portait in New York in 2006.

Nick, Aaron, Leslie and Angel speak at a Television Critics Association panel in 2006.

The siblings attend Howie Dorough's birthday celebration to raise awareness for lupus.

Bobbie Jean, Nick, Angel, Leslie and Aaron step out at a promotional event for E! and STYLE Networks in 2006.

The Carters join LaToya Jackson at the Cabana Club's Hollywood Life Lounge in 2006.

Leslie, Angel, Nick, Bobbie Jean and Aaron also stop by the Kari Feinstein style lounge.

Angel, Aaron and Bobbie Jean were pictured smiling at Rolling Stone's party honoring their 2006 Annual Hot List.