... Harry didn’t see Heloise because Heloise and Max would know that she bears a striking resemblance to her mother, who must be known to Harry. Max literally tells her not “Don’t call your mother though” on page 63. Max is extraordinarily clued up on the supernatural and Harry in particular ...
This doesn't really feel right, to me.
Offhand, I don't really see any reason why Max would feel the need to keep Harry from recognizing Martha Liberty's daughter. As you say, Max seems inexplicably clued-in to "Harry in particular," and I'm pretty sure he knows Harry wouldn't try to leverage Heloise against Martha, or put her at risk by "outing" her to any Supernaturals who might do so.
From a meta-standpoint, it just doesn't feel like there's enough
weight to such a fact; random offspring of a wizard -- even a SC wizard -- doesn't seem like that much, when Harry's got Anduriel and Outsiders on his plate, a Titan in his back pocket, and Mab's list of Honey-Do items to take care of...
I keep returning to the scene in the hallway outside Reuel's apartment, and the similar "voice from offscreen" scene. Jim's a lazy writer, and proud of it. I think "Heloise" is faerie.
Maybe Mab had another halfling daughter, one whose Choice was to become human, marry a human. Or maybe she still hasn't Choosen, marrying mortal to keep herself anchored to the mortal world as Mab increased the pressure to Choose the Faerie path... A very Sarissa-like Heloise would have been all sorts of OMG for Harry (and presumably
will be, whenever Harry gets to meet her)... not that I'm pointing to a Sarissa-alike character as "obviously the Right Answer," but an example of the sort of thing.
Unless Heloise is explicitly Mab or Lea (or Titania?), or another Faerie Bigwig (q.v. the prior "voice from offscreen"): not
actually Max's wife, but momentarily taking the role, letting mortal-Max tell the lie. But this too seems a bit unsupported and "off." Why would any such Faerie Bigwig care whether Harry thinks Max is married or not?
###
Here's another tangent: Harry drank the Kool-Aid,
literally. Jim has used this allegory a couple of times before, I think. But this time, Harry
actually drank the Kool-Aid. Somehow, I suspect this is meaningful.