I never met my great aunt Terry.

She died in 1979 from kidney cancer, only living to age 8. But my grandma Cheryl, who I call Gram, tells stories. She talks about lessons she learned from her baby sister, and passes them down to me. She makes me feel like I've known Aunt Terry all along.

One thing about us Jackson women: Even in some of the most bleak circumstances, we keep pushing forward. Aunt Terry was the epitome of this. She was diagnosed with Wilms tumor at age 4, and despite years of surgeries and chemotherapy — eventually becoming too sick to function — I'm told she remained bright, optimistic and buoyant.

Everyone has to navigate difficult situations in life, whether they're small problems or major, life-altering setbacks. Being positive and mentally resilient during these times can help you focus on the things you can control, instead of dwelling on what you can't, author and leadership coach Scott Mautz wrote for CNBC Make It in June.

"Even in her sickness, she always tried to do her best," says Gram. "I have resilience because she would tell me that you don't have to stay down ... If something [bad] happens to you, you don't have to just accept it as your lot in life."

Their strength, and my exposure to it, has changed my life for the better.

The power of mental resilience

Mental resilience helps you bounce back faster from failures or persist in the face of them, Wharton organizational psychologist Adam Grant told CNBC Make It in 2017. Without it, you're more likely to become stressed and stuck on your problems.

The resilience Gram learned from Aunt Terry defined huge portions of her life. Gram packed up her children and moved from Philadelphia to Atlanta, with no help, in her early 30s. She became a foster mom, built a career in health information technology and got a bachelor's degree online.

She started a couple of businesses along the way: designing and selling calendars dedicated to African-American history and culture in the early 2000s, and becoming a certified travel agent for her own company, Travel Excelsior, in 2010.

Most memorably, she was always there for me and my sister. When my mom fell on tough times and couldn't care for us, Gram took us in, homeschooled us, maintained her career and took care of her own sick mother without missing a beat or losing her positive attitude.

She inspires me to push through my own challenges. I left a low-income, single-parent household to become the first in my family to graduate from a four-year university. I navigated financial aid, college admissions and the real world on my own and moved across the country by myself to start a career in journalism.

None of it has been easy, but I've had Gram's example to live by. When parents exhibit optimism and resilience, their kids tend to do the same, educational psychologist and parenting expert Michele Borba told Make It last year.

Living without regrets

Aunt Terry also showed Gram the importance of living without regrets.

On their deathbeds, many people regret waiting too long to show people that they love them, Pulitzer Prize-winning author and oncologist Siddhartha Mukherjee said during a commencement speech at the University of Pennsylvania in May.

In stark contrast, Aunt Terry was Gram's personal cheerleader, often offering to help her finish household chores, or encouraging her to finish her homework. She expressed her affection for her big sister early and often, Gram says.

Another common deathbed regret: not putting your own happiness first, former hospice worker Bronnie Ware wrote in her 2011 book "The Top Five Regrets of the Dying." Yet Aunt Terry chose happiness, even while she was uncomfortable and in pain, Gram says.

Since then, Gram has been steadfast in prioritizing her own happiness, even as the circumstances around her changed. She loves to travel, and has been all over the world: Spain, South Africa, Belize and more.

Over the years, she's taught me to do the same. She constantly reminds me to nurture my hobbies and reach out to my loved ones regularly. She also practices what she preaches, showing that she loves me in ways ranging from frequent FaceTime video chats to occasional Zelle notifications.

Gram lives her life boldly. When times get tough, she still manages to keep a smile on her face. It's something I'll admire for the rest of my life.

I often imagine the figurative footprints in the sand that Aunt Terry and Gram have left in front of me, and picture myself stepping into them. I'm more resilient, optimistic and loving because of the Jackson women who came before me.

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