The main character is extremely preoccupied with gender, which is fair enough, and I'm finding it interesting where her focus lands on men and women.
When describing men, and masculine attributes, and herself relative to men, the narrator is almost always talking about their physical bodies. The very first time she describes Mrs. S she says "She is tall. From a few feet, the closest we have been, I notice I am taller." but then a page later describing Mr. S as having "Large hands, large neck. Large thighs too, I assume [...] He is taller than all of us. Mrs. S, I imagine, likes this about him especially." When borrowing Mr. S' shirt, she says "I get a measure of his size. His shoulders draped across mine. [...] The fabric reaches the middle of my thigh. I roll back the cuffs until they pinch the skin of my forearm." Mrs. S pulls down the sleeves, and "I look at my wrists and adjust the cuffs, pulling them straight, wanting the shirt tighter around my shoulders." The narrator talks about "The sexy Jesus in [the nurse's] bedroom. His body I too would die to have." On this page the man working the bar "is a big man, his cream shirt puckered across his chest." When the narrator is flirted with by the woman in the bar, seemingly mistaken for a man, the narrator observes that "At the sound of my voice she pulls back." All of these moments of gender dysphoria seem so much rooted in attributes of the physical, that's where her attention is drawn: height, size, voice.
On the other hand, femininity seems to be about performance. Mrs. S is almost exclusively described by her attire: the "luxurious fabrics" of her clothes and her nail color. When fantasizing about the dead author, she thinks of her "hair pinned back, femme-ness deceived only by a hard mouth." While the narrator describes the man at the bar by the size of his chest, she doesn't describe the physical attributes of the woman coming onto her at all, only that "one strap of a floral vest top slips down her arm" and that she is "in her flip-flops, a handbag in the crease of her arm, a pair of sunglasses balanced on her head." (Which, btw, don't Australians call flip-flops thongs?) I haven't noticed yet any woman really be described in the equivalent way the men are, like for example considering their curves or hair or anything like that.
It's not always true but I'm just noticing that pattern. The men have something unattainable to the narrator, the women perform their gender in a way the narrator notices but doesn't want to herself.