I think JB kicked the Zanny Theory to the curb very early on. Keeping her in the defense involves a whole slew of questioning that can have no answers... IMO the most damning being the glowing review of Zanny KC gave her friend YD via text message July 13th. We can see in the August 14th calls with G&C that KC does not mention Zanny by name at all, even though CA does. Also, and this is an omission not an action, I think that if there was a ZFG who had any connection to the crime at all, JB would have been moving heaven and earth to get her description out there so LE could bring her in. He would have had KC tell him everything about her and gotten out any tips or pictures or sketches or favorite brands of coffee that he could to see that a real ZG was brought in and questioned. Instead, I think he asked KC, should we waste dollars and hours searching for this person or move on to a different defense? And she said move on. MOO.
So for these questions, I don't think she (or the JB staffer who writes it for her ) will reveal anymore attributes of the fake nanny, because JB doesn't want to go there. Of course there is truth in the statement "Lying doesn't make you a murderer." From a practical standpoint I think JB knows that she may have to take the fall for lying to the police but may still be able to somehow wrangle reasonable doubt for murder if she drops the Zanny connection.
For the life of me I don't see why they don't drop the countersuit though. Meantime, they just need to say this ZG was not her nanny. That's true enough, and then she can "forget" any pertinent details about how the "real" nanny looked, lived, or behaved.