Her body was never found during the pirate raid so do you think that she actually died?
She was researching either the precursor civilization or the Ancients so maybe she got sent somewhere??
And of course there's always the theory that she's somehow connected to Seto.
I think she either died in the attack trying to save Seto or someone else, or was wisked away somewhere by Tokimi or Tsunami.
We'd probably need some more info, specifically a better grasp on what is going on in Washu's pre-anime novel...
If I had to make a ballpark left-field guess, I'd definitely say Seto is involved in this somehow, whether she was saved by Naja, is naja or even talked to Naja before she died...
Ridiculously scary how similar she looks to Noike....
(http://img708.imageshack.us/img708/7397/gxp810.jpg)
wow, yeah....
Well Noike is basically Naja's clone so it's not surprising that they'd look similar.
I think that Lady Seto and Noike are related to Naja. Naja disappeared sometime after Space Pirates have attack the planet where she was helping a team of archeologists who were studying a site of a precursor civilization.
You may want to check the GXP novel thread it appears to answer some of this as it has been confirmed Naja's mind is inhabiting Seto's like Kagato and Noike.