Selena Gomez is giving back this holiday season, teaming up with Ryan Seacrest to help families in need through the talk show host's KIISmas Giving campaign.

According to his website, the 'American Idol' host heard about the story of a 13-year-old girl named Hana, who suffers from a fatally genetic disease called progeria. The rare illness dramatically accelerates the aging process, and the average life span for those with the disease is 13 years.

Upon hearing that one of Hana's dreams was to meet Gomez, Seacrest organized a surprise visit from the star at Children’s Hospital Los Angeles. "Selena is one of the most generous people I have ever met in my life," Seacrest said. "She was recording her album here in Los Angeles, and she was heading to the airport to fly up North for a concert. I told Selena Hana’s story, and she stopped recording her album in the studio, and went to meet Hana in the hospital, then flew to her concert."

The visit was a complete shock to Hana, who cried the moment the 'Who Says' singer left. "I can’t believe it," Hana said. "I had so much to say, but I didn’t want to cry in front of her because I didn’t want to look like a baby." The 13 year old's dreams literally came true, and was described as "the best Christmas ever.”