。
She poked her face out the window.
Literal
She [topic-は] window [from-から] face [object-を] put-out.
顔を出す is a vivid set phrase — literally 'put out one's face,' meaning 'show up, drop by, make an appearance' (figuratively) or 'poke one's face out' (literally). Here, with から, the literal reading dominates: poking one's face out the window. The figurative use ('drop by') is also very common in social contexts: パーティーに顔を出す ('drop in on the party').