I thought everyone had realized she was mini quite a few chapters ago? Wasn't like it was that hidden by the time she got amongst the cars. Could be a vast number of reasons why though.
@zokoi19
If that's the case, is she one of the abnormal thing that the red fog brought upon the world? Cuz from what she said, her species never met human after all.
What she said isn't reliable, she doesn't have any particular historical knowledge. Even if humans had somehow been shrunk instead and mostly wiped out/forced into hiding, that could easily lead to their true history being lost. Even more so if the reason was something bad that they wanted to cover up, just don't tell the next generation.
Of course normally something her size wouldn't be capable of that level of cognition and everything else, can't just shrink down a human in reality. If the author doesn't plan to handwave it, then some sort of extra dimensional/nanomachines/simulation/remote support biobot creation/synthlife thing would need to be going on with her.
Maybe though this will also just be one of those postapoc, series where no big mysteries are ever clearly resolved, it's just about the journey and what she sees/gets to. Why humanity ended might never be made clear at all, she may never meet them.