Well, if I may, I would advise you to don't take the "stripped of her bending" route yet : if in the next episodes of Korra it turns out that Amon's "energybending" isn't permanent, or is reversible, it will break all the drama of Zeiryuu's fate.
Although if you want your story to be the more canon compliant possible, her being stripped of her bending, but still alive, wouldn't make Zuko depressive to the point of death, and that would explain how Azula could have been shipped back to the FN.
Because maybe I overestimate her, but if Amon killed Zeiryuu, I don't think Azula would accept to come back to the FN without at least trying to find and punish Amon! I mean during her whole stay in house arrest, Zeiryuu has been the only one who saw her as a human being instead of a potential threat, she's also the one who helped Azula to be a better person. Azula own so much to this girl, I wouldn't even be surprised if she consider Zeiryuu a little like her daughter(like Iroh toward Zuko). And then someone come and kill this prodigy, and she would just obey Zuzu's order and nicely come back to the FN, probably back on house arrest? Sorry, but for me that seems impossible!
But if Zeiryuu has been stripped of her bending, then I could visualize Azula coming back with her to support her, like Zeiryuu supported Azula in her darkest hours, that would be a nice way to pay her back!
Unless she just came back to the FN to plot the retaliation alongside Suzaku, Suzaku storm the northern side of RC, and Azula the southern side(toward the ocean, if the equalists tries to get out by see, she could zap them using the sea as a conductor, more efficient!). One week later, the actions of the Building Companies rised a 120%!