Yes, if Poet doesn't leave soon then she'll most likely just become more and more ground down, both by the rapes, and by his moods and anger. Constantly trying and failing to hold boundaries just isn't sustainable forever – eventually she'll run out of fight and give up, and just shrink her wants and her needs more and more, trying to placate him, her bar for 'acceptable behaviour' lowering as time goes on.
As the children get older they'll notice their parents' dynamic more acutely, and learn that's how a relationship should look – with a submissive woman fawning to an angry man – and will subconsciously seek to emulate it in their own lives even if they hate to see it in their parents.
In addition, as they get more independent and stroppy, their father will shout at them even more, becoming more verbally abusive and making their home an even less welcoming place to be.
If they're lucky, his moods will just motivate them to leave home as quickly as possible – if they're unlucky, they'll end up in abusive relationships and other dangerous situations while still teenagers (like @BuckChuckets said upthread, ask me how I know).
Hopefully Poet will be able to leave within the next few years, before this happens.