Evha Jannath, from Leicester, is said to have fallen as she stood up to change seats on the Splash Canyon ride at Drayton Manor, in Tamworth, Staffordshire.
The girl, who attended Jameah Girls Academy in Leicester, was “dragged under the water by the current”, said witnesses.
Evha was recovered from the water and received advanced life support from ambulance crews before she was flown to Birmingham Children’s Hospital, where she died.
Her uncle, Abdul Hadi, today said: “She is my beloved niece. Please everyone pray for her.”
A friend of Evha said the girl had almost missed the day out because she had been ill in the run-up to the trip.
Drayton Manor remained shut yesterday as a mark of respect as investigators from the Health and Safety Executive were at the scene. The school also remained closed for the day following Tuesday’s accident. According to one parent at the Jameah Academy, the girl fell from one of the boats when it hit a rock. She said: “My daughter said there were four other girls on the same boat with the girl and the teacher’s boat was behind the girls. When the girl got up to change seats, just then it hit a rock and she got knocked out of the boat and fell in the water and the water currents dragged her in. The kids started screaming and told the staff at the park that their friend had fallen in the water.”
The brother of another pupil in the boat said: “My sister was saying that Evha stood up in the boat and looked like she was moving seats. Then she looked back and she was in the water. It happened in an instant. For the past few days I don’t think Evha had been going to school because she wasn’t feeling well.”
In a statement her school said it was providing “support to pupils and staff” and asked that the girl’s family and the school community were given “time to grieve”. Drayton Manor’s company director George Bryan, whose grandfather opened the park in the Fifties, said they were “truly shocked and devastated” by the death.
The ride opened in 1993 and features up to 21 boats, each with a capacity of six people, and offers “a wild ride” with “fast-flowing rapids”. Riders must be at least 3ft (0.9m) tall, although those under 3ft 7in (1.1m) must be accompanied by an adult.