The plant's posture doesn't say "Thirsty!" to me.
The sun leaves would be drooping straight down as the growing tip laid over.
Flushing requires a MINIMUM of enough water to fill your pot, at least once. You are trying to wash away something that may be poisoning your plant. It can't hurt, but might save your girl.
Once she seems to have recovered, you can feed her, but lightly, at first.
Be gentle.