John Green tells The Boston Globe in Sunday's edition that he received a phone call about the transplant, but he doesn't know any other details about the donation.
He says the call "really lifted" his spirit and he and his wife are proud parents once again of their daughter, "who has done another amazing thing."
Nine-year-old Christina Taylor Green was born Sept. 11, 2001.
She had just been elected to her Tucson school's student council, which is why she went to see Rep. Gabrielle Giffords.
A spokesman for the New England Organ Bank tells the Globe he can't comment on donations.
The Arizona Republic reported Friday that Tucson's Bishop Gerald Kicanas told the crowd at Christina's funeral that her organs had been donated.