Diane is a character from Jaws 2 and the only person to die because of her own incompetence rather than the shark.
Diane is a waterskiing driver. After her friend Terry is devoured while waterskiing behind her boat, she attempts to flee, but the shark hits the transom and knocks her to the floor of the boat. After screaming and stumbling, Diane throws a gas tank at the shark, inadvertently dousing both her and the shark with gas. She then shoots the gas-drenched shark, and the shark's cheek catches fire. In the ensuing panic, Diane's pants catch fire too, and the boat suddenly explodes. Later, as Chief Martin Brody notices charred remains of her boat on the beach shore, he goes into the water to bring some of it in, he is then met with an awful shock as he discovers her burned corpse among the wreckage.
- It is implied that she may be Terry's mother. The Wikipedia page lists this.