I'm really split on it, honestly, and it's hard to put down why. I can't really argue with anything you brought up, though. Only thing I'd say is if you mean the
event, I think she'd intervene there, too, at least with how clearly batshit both were acting. It just seems like there's one side of her that would look at it unfavorably specifically because she knows better now and has (mostly?) distanced herself from the Yakuza, and her old accomplices and way of life. She's still not a perfect person, and can't kick cigarettes and alcohol, but she's tried to generally be 'better' in a sort of 'good enough' way. No hurting people, living honestly, kicking the funky chalk/needle habit, and as a compliment to her character (holy fuck, Yakuza mommy) she's done pretty well. That makes me question if he'd said "Yeah I had sex with her" instead of kissed her, what she'd say. But on the other hand, her overall attitude is nonchalance and that "I've seen worse" sentiment like you mentioned. I'd really like to know, although that might mean another awkward scene with her walking in on something blasphemous.
Also, I did completely forget that he told her about that. I thought most recently her reservations were because of Sara though? Of the top of my head I can only recall Yuki being okay with him, like, hanging out with the girls way too much and whatnot. Anyway, if you keep handing me Ls I'm gonna ask for a punch card or something.