In the middle of the last episode of the "Mayoi Snail" arc, we are told that Araragi is being led astray by Hachikuji after he didn't want to go home, because he was:
feeling awkward because it's Mother's Day, fought with [his] sister, and didn't want to go home
Moreover, past 14 minutes into the episode:
The condition for encountering a lost cow is to have a desire not to go home. But everyone feels that way at some point. After all, everyone has family problems.
So it doesn't have to be a particularly strong lack of desire to go home -- it doesn't have to be something "big" enough to lead to another appearance of Black Hanekawa.
Having thus obtained an explanation for why he saw Hachikuji from Senjougahara, Araragi thinks of Hanekawa, and concludes to himself that Hanekawa was able to see Hachikuji because of her family problems:
And so did [Hanekawa]. Carrying the weight of bad blood and strain within her family . . .
So it simply looks like while Hanekawa's stress with her parents dissipated somewhat after the first Black Hanekawa possession, the underlying problems were never resolved. For instance, in the beginning of "Tsubasa Tiger", which is in the second season of the series and which is after Bakemonogatari
we learn that Hanekawa (still) doesn't have a room of her own in her house, and sleeps on the floor
So, at the very least, it looks like Araragi thinks that Hanekawa's ability to see Hachikuji is entirely to be expected, and not a cause for concern about new developments. It's possible that Hanekawa is keeping her friend in the dark about things -- if I'm not mistaken, in the "Suruga Monkey" arc, we see her lying to Araragi about where she is. But even if something new has come up between her and her parents, it probably isn't anything out of the ordinary, at least in that we never see any more detail go into this in the anime and in that it never turns into a massive crisis on its own.
