It’s probably very wrong to encourage this, but I think it’d be pretty fascinating — the effect of insta-motherhood on Korra, how she’d reconcile it with her duty as the Avatar, how she and Tarrlok would raise an earthbending or non-bending little girl (Korra is such an earthbender type herself that either could be adorable), and … er, all the things. And ha, maybe shades of Chiaroscuro for Amon, too, only no forewarning and no potential bloodbending? I don’t know, but it sounds awesome.
LOL, “Councilman Tarrlok abducted me with bloodbending and then we adopted a baby together” is one of those things that all the context in the world can’t really explain.
Maybe you could write it after Strings.