I thought that line meant a narrower betrayal. I assumed that because she looked different that the part that she belonged to another crew that crashed on the planet (or were crashed by Krall/Edison) was still true, only that they were all with Krall's group now. Like that maybe that alien tech was drawing in ships and crews to change them for this weapons system, and only those who didn't join were drained for their energy. And that was why there were so many people.