1.
Text: (Thoughts) The fox girl pushed herself upright, flailing like a spoilt child at the girl, before turning tail and running through the door.
Situation: conversation between 5 peoples. 2 of them are semi-cat humans (they have cat's ears and tails). `The fox girl` is one, who was shocked by the subject of the conversation.
Problems:
Can't find appropriate translation for `flailing like a spoilt child`.
Can't understand, how can someone `flail at the girl`?
Is `turning tail` means exactly `move tail from side to side`? Or is `turning tail` means `turn around`?

*5 people. "Person" is considered the singular, and "people" is considered the plural. In special situation one can say "persons" and "peoples" though.

Anyway, "spoilt" is some form (that I should totally know what is, but I don't really) of the much more common word "spoiled". When talking about food, it means expired, but a spoiled person, is one who is...arrogant, I guess. If someone gives their child everything they ask for, the child usually gains a "spoiled" personality. It's mainly connected with entitlement. It's often used in regards to children. Flailing means swinging around. (google "flail", medieval weapon). I imagine the person's arm are swinging around violently. "turning tail" sounds like a southern U.S. accent to me, very strange way to say that she turned around. I think it was meant to be a pun, since... You know... Cats... and tails...