For me, I would swap the clauses so that the child appears first and then the village:

A dreamy child must fight to survive when her village is destroyed by war.

Then I’d try to hint at a specific goal and specific antagonist.

A frightened child must escape the clutches of human traffickers when they destroy her village and murder her parents.

An imaginative four-year-old makes a harrowing journey to a neighbouring tribe when her village is destroyed by militants.

An isolated child must use all her smarts to survive in the wild when her village is ransacked by imperialists.

Or whatever suits!