When Warren Buffett announced in 2006 that he would give away his billions, he was flooded with individual requests for help that still flow in today.

Doris Buffett attends the Women for Afghan Women 12th Anniversary protecting women’s rights beyond 2014 at Tribeca 360 on May 30, 2013 in New York City.
Instead of tossing the letters aside, Buffett packages them up and sends them to his older sister Doris. With the help of seven women,her Sunshine Lady Foundation scrutinizes each request to find people who have come upon bad luck through no fault of their own.

“She just believes that a lot of people got short straws in life, and she wants to help them,” Warren Buffett said.

It’s rare for philanthropists to respond to individual requests, said Northeastern University professor Rebecca Riccio, who teaches philanthropy and interviewed the siblings last year. Buffett, 83, and his 86-year-old sister worked out the unusual arrangement because neither wanted to disregard the requests, but Buffett also wanted to focus on running Berkshire Hathaway.