She didn't want to 'give full vent to' her feelings. [=let her feelings out completely]
She 'vented' her frustrations by kicking the car.
She needed to find a 'vent' for her frustration.
(..) - We don't know that. - That's the only way. We'll move in pairs. We'll go step by step... and cut off every bulkhead and every vent... until we have it cornered, and then we'll blow it the fuck out into space. Is that acceptable to you? - If it means killing it, yeah. (..)1979 Alien
(..) Parker, can you rig... three or four incinerator units? Give me about minutes. I'll do it. - Who gets to go into the vent? - I do. No. You and Ash... take the main air lock. (..)1979 Alien