Britney Spears’ niece was ‘trapped by her seatbelt after ATV plunged into a pond’ as she remains in critical condition Jamie Lynn Spears’ eight-year-old daughter was trapped by her safety belt after the ATV she was driving plunged into a pond on Sunday, according to a local police report. Jamie Lynn Spears poses with her six-year-old daughter Maddie and Minnie Mouse in front of Cinderella Castle at the Magic Kingdom park August 14, 2014 in Lake Buena Vista, Florida.