I had to look up what "fifth" and "bourbon" are, and what that means, and what the effects would be.
So it turns out that a fifth is a fifth of a gallon, or about 750 ml. Exactly 750ml is called "metric fifth" and the usual size used nowadays.
And bourbon is an american wiskey made of 51+ % of maize/corn, plus possibly other wheats, destilled to at least 40% alcohol, and stored for an unspecified amount of time but ideally apparently 4+ years in containers made from a specific wood, which results in the whole thing having a specific color.
So thats 750ml of american wiskey with at least 40% alcohol, or at very least 300ml alcohol.
According to an online calculator I goggled, assuming that Faye weight 80kg, she'd be at 4.95‰ , sober after 30 hours. With 100kg it drops to 3.95‰ and 25 hours.
According to another google about the effects of alcohol levels at 2.5‰ loss of consciousness happends and at 4‰ death is possible. So with 80kg she'd basically be dead for sure and with 100kg she might still have a chance of survival.
Possibly Faye stands better chances of survival because she's an experienced drinker and her body has adapted somewhat. Either way she'd be drinking herself into a stupor and beyond and not be able to properly function for a full day.
As someone who never drinks and to which "a fifth of bourbon" meant absolutely nothing it was very helpful to understand what is going on. Maybe somebody else felt the same way.
P.s.: Thanks to pwhodges for the permille sign ! 😁 I only know windows key + ".", which doesnt give you any special characters, only smileys. 🙂