Delaney, known to her family as Laney, suffered from a rare form of leukemia, the Reading Eagle reported. She turned 8 last Friday.
"We are devastated by the loss of our Laney. She was our angel. We will miss her smile, her laughter, and the way she would light up any room she was in," Christopher Winters said. "We are eternally grateful for all of the love kindness, prayers and support that we have received from people across the world. You will never know how meaningful it was for all of you to rally around Laney."
Laney's parents were told recently she had only a short time to live. Last Saturday, thousands of people gathered on the street outside the family's home to sing Christmas carols, one of her wishes.
As many as 10,000 people may have participated, the Eagle said.
Laney also got a birthday telephone call from Taylor Swift arranged by the Make-A-Wish Foundation.