Cyn is a sharp witted kid who is depressed about her mom's disappearance.

She is emotionally guarded, and tends to come off strong and indifferent.

Her speech is concise, matter of fact, and to the point.

Cyn is probably the most balanced character. She is surrounded by very extreme personalities. She's usually level-headed and focused on her goal—finding her mom. She is very determined and brave. She's a good kid, but not a goody-two-shoes.
I said, "[She] tends to come off strong and indifferent," but don't mistake this for bratty or snotty; she just comes across like she believes in whatever she's saying. She's not particularly charismatic or confident, but knows which questions to ask. She's very observant and intelligent.