Gabrielle is chosen as Fleur's hostage for the second task. She is bound tightly to the tail of the statue of the merperson in the lake. Gabrielle appears to be in a deep sleep; her head is lolling onto her shoulders, and fine streams of bubbles issue from her mouth. Gabrielle is retrieved from the statue of the merperson, and is towed back through the lake by Harry, alongside Ron. She looks scared and confused as they break the surface of the lake, and is pulled through the water by the two boys towards the bank. Gabrielle is greeted by her frantic sister when they eventually reach the bank.
Gabrielle and her mother visit Hogwarts on the day of the third task. They meet Fleur in the room off the Great Hall on the morning of the task; she waves at Harry when he enters the room. Along with the other spectators, Gabrielle makes her way to the Quidditch pitch after the evening feast to watch the third task.