she's both. neimodians=duro.
here's an excerpt from a particularly good sw site on the officiality of the EU....
Lastly, we have a the case of the Neimoidians and the Duros, who have been declared as the same species. In the years between ANH and TPM, Lucasfilm had determined that the gray alien spacers in ANH were "Duros," and the Official materials had continued taking that stance. When TPM was released, the Neimoidians looked similar, but not exactly the same, as the Duros. This was all well and good until Lucas decided that the aliens in ANH were the same species as the Neimoidians. As a result, instead of trashing or fouling up all of the vast library of Classic Trilogy era stories featuring the Duros, LFL inserted a single, small mention—just a couple of sentences—into the Nar Shaddaa entry in Dark Horse’s Dark Empire Handbook, in which the transformation of Neimoidian society into the Duros society is mentioned. With a simple addition of sentences, Lucasfilm executed Lucas’ decision without so much as batting an eye over the fact that this gives new meaning and resonance to the events of Balance Point.
check out
http://www.omegacron.com/starwars/eu/canon.htm)
for more details.