Tension builds in Conversations with Friends, but where will it lead?

Some thoughts about the second part of Sally Rooney's Conversations with Friends: The narrator, Frances, gets seriously ill at the outset of part 2, with what at first all readers (and the characters!) assume is an unintended pregnancy and a miscarriage, but no, it's some other as yet unexplained internal ailment. This makes me nervous, but it's astounding how little the characters, including the narrator herself (and her oce-cold mother) react to this malady; amazingly, her mother leaves Frances, in agony, alone in the hospital to go about her daily business such as it is. Second, we get another look at Frances's estranged father, who is living in utter squalor and who fails to come through on a promised "allowance" for Frances, but somehow she's still loyal to him - but is she in search of or in need of a father figure? Well, against their best intentions, she and Nick continue the affair - but he does not seem particularly fatherly (he's 10 years her senior, if he's not lying about his age that is). There's something utterly strange about their seemingly clandestine relationship. They both live in dread of Nick's wife's (Melissa's) finding out about their affair - yet it's amazing what risks they run and how many opportunities they have to get together w/out her knowing, or at least suspecting something's going on; I think this is intentional (on Nick's part) and that Melissa knows about the relationship and tolerates it in the interest of holding their marriage together - probably as she engages - with F's friend, Bobbi? - in an affair of her own. If not, then she's just an obtuse character, which doesn't seem in keeping with her sharp intelligence. Meanwhile, Nick is built up as a childhood genius, who appeared on some national show at age 10 or so offering commentary on Plato, but where did that intelligence go? He seems at present more like a hunk-like dolt. He has nothing to say, for example, about his work in theater, about the plays he's been in, about anything he's ever read, including Frances's poems. Rooney has built a lot of tension among the characters in this novel, but so far - 3/4 through the 300pp book - the tension holds and the characters have not changed much over the course of the narrative. Something's got to give.