Madison, her grandmother and aunt were hurt in the crash.
They were in the crowds at the OSU Homecoming parade.
Adacia Chambers, 25, was arrested in the deadly crash.
SKIATOOK, Oklahoma -
The family of a 7-year-old child injured in the OSU Homecoming parade tragedy said an unknown woman saved the little girl's life. Madison Atwell was in the crowds Saturday morning when a driver plowed into spectators, killing four and injuring dozens more.
Maddie, as she is known by her family, is a second grader at Skiatook Elementary. She suffered head injuries and broken bones, but her grandmother Sue Buttrey says it could be much worse.
The family says Maddie is alive because a stranger stepped in and picked her up, shielding her from greater harm.
They call the woman Madison's guardian angel in a statement Sunday morning.
"Thank you all for the prayers, love and support shown for my g'daughter, Madison, through this difficult time. Her mother, Amy Brown, and family are moved by the outpouring of love from the Oklahoma community. Our prayers are with Maddie's guardian angel, the other victims as well as the families affected by this tragedy."
Madison was life-flighted to an Oklahoma City hospital where she is said to be in fair condition Sunday. Her aunt Kayleigh Atwell, 20, has a broken knee cap that is said to require surgery. Kayleigh is an OSU student.
Grandmother Debbie Atwell suffered a broken rib and other trauma.
The family initially thought the guardian angel may have been one of the victims killed Saturday morning, but later said they believe it was one of those critically injured. Bonnie Stone, her husband Dr. Marvin Stone, Nakita Prabhakar and Nash Lucas were killed.
Stillwater Police arrested the driver of the car that crashed into the crowd at the intersection of Main and Hall of Fame. Adacia Chambers, 25, was booked on suspicion of driving under the influence.
Police say when toxicology results come back, they expect to present additional charges to the Payne County District Attorney's Office.