。
She told the children an interesting story.
Literal
She [topic-は] children [target-に] interesting story [object-を] let-listen-to-as-favor.
An elegant little construction: 聞かせる (causative of 聞く 'listen') means 'have someone listen / let someone hear,' and ~あげる adds the benefactive shading ('as a favor for them'). The full ~てあげる + causative captures 'told them a story (as a treat for them).' Common in parental contexts, where the parent's act of telling is framed as a kindness given to the child. The verb 聞かせる, despite being causative, often translates as a simple 'tell' in English when the content is a story or news.