A Georgia grandmother has died after she jumped into a lake — despite not knowing how to swim — to try and rescue her drowning 13-year-old granddaughter, authorities and family said.

Stephanie Walker, 49, and her granddaughter, Makayla Prather, had been fishing together in West Point Lake on June 11 when the teen somehow ended up in the water and “became distressed,” news station WSB-TV reported.

Walker dove into the water to save the 13-year-old, but also began to struggle.

First responders who were summoned to the lake at 2 p.m. found the grandmother not breathing and rushed her to Well Star West Georgia Medical Center.

Prather’s body was recovered from the lake by divers at 7:30 p.m. after a five-hour multi-agency search.

Walker’s son, Rodrikeus Prather, wrote in a Facebook post that his mother rushed into the lake in a desperate bid to save his niece — despite not knowing how to swim.

In another post, Prather described his late mother as a “super hero.”

Walker’s daughter, Shawanda Prather, who is Makayla’s mom, also praised the “brave” 49-year-old for doing all she could to try and save her granddaughter.

Walker spent a week on life support before succumbing to her injuries on Friday, WSB-TV reported.

Makayla is survived by her mother, stepfather and three siblings.