A daemon's gender seems to be separate from its shape, though. Like, a child's daemon takes all sorts of shapes but always has the same gender (and apparently all of the animals are of the sex that matches the daemonic gender but I don't know if we have enough data to be sure).

So if a daemon wanted to take the form of an animal that didn't have binary sex, I guess either it wouldn't be able to because there wouldn't be an appropriately-gendered form, or it would keep its original gender in the non-binary-sexed form.

*fanwanks about a series I haven't read in years*