The Prehistoric Era was a fantasy novel, but there was no specific description of whether or not Ning's parents had died in the end. The plot of a novel usually changes according to the author's arrangement and the development of the story, so there may be different results.
Batman's parents were shot and killed by a criminal in an alley. It was a random act of violence that had a profound impact on Bruce Wayne's life and led him to become Batman.
In the comics, Batman's parents were killed when they were walking home one night. A criminal approached them, demanded their valuables, and then shot them both. This tragic event led Bruce to vow to fight crime and seek justice.
Neville would become more confident. Knowing that his parents are healed, he no longer has that underlying pain and worry. He would be more assertive in his actions and decisions, and might even take on more leadership roles at Hogwarts or in the wizarding world in general. For example, he could be more outspoken in the DA meetings.
In some fanfictions, James Potter's parents could die in a wizarding battle against dark forces. Maybe they were targeted by some dark wizards who wanted to eliminate the Potter family's influence in the wizarding world.
In a particular fanfic, James Potter's parents might die in an accident. For example, they could be traveling using some form of wizarding transportation, like a flying car or a magical carriage, and something goes wrong. A malfunction in the magic that powers the vehicle could lead to a crash that takes their lives.