The Annotated Nexus - Pages 52, 53
53.0 A few days later, Henry overhears an argument: Stasia has apparently been squandering a secret fortune. Mona is angry enough to leave. Stasia seems unusually calm about Mona’s reaction, and unusually nice to Henry.
52.1 bitched up
I actually hadn’t heard this term before, although I’ve heard variations of it. According to the Oxford English Dictionary (by way of Roxanne.org), the use of the word bitch as a verb meaning “to spoil” has existed since the mid-1800s. The exact term bitched up was given to a character in the Ben Hecht co-authored play, The Front Page (according to The Crowd Roars, the 1931 film version created a stir when this sharp language was spoken by actor Pat O’Brien). Oxford lists six other published uses of this term between 1929 and 1960.
52.2 “You don’t belong in a place like New York.”
This evaluation is thrown at Stasia by Dr. Kronski, who furthers that she doesn’t “fit in anywhere.”
Stasia is not from New York, and hadn’t been there for long. On page 587 of Plexus (the prequel to Nexus), the character of Anastasia is introduced as having “blown in from the Coast.” This would be the East Coast, as it’s currently believed that the real Stasia came from Virginia (see this post, which links to further speculation).
52.3 "They don’t know the meaning of the word [friend].”
Kronski looks at Henry and Mona with contempt as he warns Stasia about their bad influence. Kronski, who was based on real-life Dr. Emil Conason, had earlier criticized Henry and Mona for lacking moral turpitude [50.5].
I wonder where this bitterness comes from in the Kronski character. If truly based on Conason, it seems odd—he and Henry would be friends right into the 1960s. June (“Mona”) thought highly of him  and was given free medical care by him when she was physically and mentally ill in the 1950s and 60s . Back in the 1920s, shortly after being married, Henry and June had lived with Emil and his wife in their New York apartment. Yet Conason is also given an ugly treatment as a shady medical practitioner named Prigozi in Miller’s long-unpublished Moloch. (That character also fires off judgemental outbursts in Moloch, i.e. p. 26: “Psychopaths! […] You’re a pack of nuts…the whole lot of you!”) Was Miller being funny, unflinchingly honest or just mean-spirited with his unflattering fictionalized treatment of his friend? This is worth examining in a future post.
While fishing for a cigarette in Mona’s purse, Henry finds the letter from Stasia. I’m not sure what Miller’s preferred cigarette was during his early New York years, but there are about a dozen references to him smoking in Nexus; once puffing on a Benson & Hedges that had is offered to him (p.108). Later in Paris, he would make a habit of smoking Gauloises Bleues 
53.1 thousand dollars
Mona is upset that Stasia had given one thousand dollars away to “some worthless idiot.” Henry wonders where this fortune had come from. On page 51, she mentions that she receives money from her “guardians.”
According to the inflation calculator, $1,000 in 1926 would equal $11,622 in 2007. This seems like an outrageous amount for a young 20-something female waitress to have in 1926. Her “guardians” must have been very well-heeled. Stasia’s reason for giving this away? “What’s money good for if not to throw away?” This is consistent with her action in 51.1, when she tore up a check that could have paid for rent.
 Orend, Karl. 2006. “Alfred Perles and June Mansfield: Some Unforgiving Encounters in the Shadows of Henry Miller.” Nexus: The International Henry Miller Journal. James Decker, et al, editors. Vol. 3: p.75.