It's just that you would think someone like her (a.k.a., a flight specialist) would be more prepared.
Times were a hell of a lot different then.
What you could anticipate was limited due to limited technology amongst other things and it was hardly like there were many places to fill up a car, never mind an aeroplane.
Plus, her journey was something never done before; a flight around the world at the most outerly point of it - the equator. But that's not all, the only major type of planning done for her was a fuel tank swap, for a larger one. Plus, the radios signals failed at a certain point so she had no other means of coordinating her position except for her co-pilot, who was navigating. But without constantly updated coordinates from the base, there was only so much he could do.