The Warren Buffett-led Berkshire Hathaway Inc (NYSE:BRK)(NYSE:BRK) recently became one of a limited number of companies to pass the $1 trillion market capitalization.

The rising valuation of the conglomerate over the years has helped add to the wealth of the many investors who have trusted the vision of Buffett, including his sister Bertie Buffett Elliott.

Investing in Berkshire Hathaway: Elliott, who at 90 years old is the younger sister of the legendary investor, shared her story of investing in Berkshire Hathaway in a May 2024 interview.

Buffett credited his sister in a Berkshire Hathaway annual letter as being a smart investor and someone who reads newspapers every day. His sister realized that it was her older brother who was the smart investor and went all-in on believing in his investment strategy.

"I figured out that Warren was better at it than I was. That was easy," Elliott recalled in an interview with CNBC's Becky Quick.

While the move seemed simple in hindsight, Elliott revealed it took some adjusting, particularly when it came to Berkshire Hathaway's no-dividend policy.

"I was in a place in my life where I wanted some dividends," she explained. "Once I got over that hump and realized... I can decide when I declare a dividend... by selling some stock. And it's capital gains instead of regular income tax. And that's good."

This strategy allowed Elliott to customize her financial withdrawals while benefiting from the growing value of Berkshire Hathaway stock. Over time, she became confident in her decision to stay fully committed to her brother's company, despite occasional temptations from brokers and investment opportunities.

"Luckily, I didn't even have to think about it much," Elliott said. "I knew I was all in with Warren and still am all the way."

For Elliott, her relationship with her brother goes beyond business. Despite his global success, she still views him as "my big brother." While the world may see him as a financial titan, Elliott feels fortunate to have grown up with a sibling who has always looked out for her. "He's always been a wonderful big brother. And I love him. And I feel so lucky that he's my big brother."