。
I think she'll be back right away.
Literal
She [topic-は] soon return-come [quotative-と] think-polite.
Polite ~と思います ('I think') wraps the prediction. と is the quotative particle marking the embedded thought 戻ってくる ('come back') as the content of 思う. The ~と思う frame (polite ~と思います) is the standard way of softening any assertion into a personal opinion — useful in business and polite contexts where flat-out predictions might feel presumptuous. 戻ってくる, with the inward-directional ~てくる, locates the return as oriented toward the speaker.