The character who says basically nothing! She is also one of the lead character's [Alex's] little sister, she cares for everyone and is still an innocent little child. 

EMBRACE THE SMALLNESS

If you want little lines but still want to make the audience cry this is your role. She is little, I'm talking like 6.

If you could not tell from the lines, she's gonna lose some family, so know that is the emotion you need

Again, she is 6
She does eventually give some exposition
Emotion... just raw emotion.