she drank all of her water before the end

in the first few days in the arena, before it was widely known that there were poisons all around, maysie drank water from a spring and spent the next series of days horribly sick. she managed to drag herself into a good hiding place to wait it out - - that she didn’t die of the poison or of dehydration might be considered something or a miracle.

      in the end, it turned out to be more help than hindrance. the sickness
      passed and now she knew. from that moment on she learned to use the
      poisonous arena to her own advantage, dipping her blowdarts in the
      water, the flowers, anything she could find, and using them against the
      other tributes as they threatened her.