i dont think that it is male or female (per se) but its just on part of the glados mainframe, because its suggested that the glados you see is only one hub of the whole AI. and its probably just voice distortion rather than anything. the thing im wondering about is that who opened the portal to the outside?
So GLADoS was telling the truth, and I'm guessing that the thing she was talking about [When she said the world changed) was the combine invasion