Doesn't try to initiate, fair. Doesn't meddle, fair. But everyone in her house presumably knows MC spent the night at Alex's apartment (they'd know, in any event, that he didn't come home, and they'd know he spoke with William--it doesn't take much imagination to reach the correct conclusion, even if MC didn't outright say that's where they met, which he likely would have). Does she know what happened? She has to at least have a good guess.
Luna, though, I'd have to agree--though part of that is the relative paucity of content with her to begin with.