Jamie Lynn Spears' Daughter Seriously Injured in ATV Accident

The 8-year-old was riding in the off-road vehicle when she flipped over into a pond.

Britney Spears' 8-year-old niece is in "extremely serious condition" following an ATV accident Sunday.

Read: 1 Hiker Dead, 4 Others Injured After Plunging Down Icy Mountain

Maddie is the daughter of the “...Baby One More Time” singer’s younger sister Jamie Lynn. The little girl was reportedly riding in an off-road vehicle during a family hunting trip in Kentwood, Louisiana.

A source close to the family told Inside Edition that Maddie was underwater for minutes. She was airlifted to a nearby hospital.

Jamie Lynn grew up in the shadow of her superstar sister but became a star in her own right with the nickelodeon show, Zoey 101.

In 2007, she made headlines and drew a ton of criticism when she got pregnant at age 16.

While she was pregnant, Jamie Lynn came under fire for riding in an ATV with the baby's father, Casey Aldridge. They didn't wear seatbelts or helmets — and had a gun.

Jamie Lynn, who's now 25, was reportedly not with Maddie at the time of the accident.

Read: Girl, 15, Who Skipped School to Have Sex With Friend's Dad Says It Was a Mistake: 'It's Illegal for a Reason'

In 2015, there were a staggering 97,000 ATV-related emergencies. An estimated 28 percent of those injuries involved children under the age of 16, according to Consumer Product Safety Commission.

A spokesman for Jamie Lynn said: "Right now the Spears family asks that everyone respect their privacy during this time and [the family] appreciates all the prayers and support."

Watch: Britney Spears Superfan Spends More Than $80,000 in Cosmetic Procedures to Look Like His Idol