、。
She closed her umbrella and broke into a run.
Literal
She [topic-は] umbrella [object-を] closed, started-running.
走り出す is a compound verb ('start running, break into a run'), built from 走る ('run') + 出す ('start [doing]'). The compound auxiliary ~出す attached to a verb stem typically marks a sudden start: 笑い出す ('burst out laughing'), 泣き出す ('start crying'), 飛び出す ('leap out'). The te-form chains the umbrella-closing as a sequential prelude to the run. A nice cinematic moment: a small action followed by a sudden burst of motion.