Need advice for part in The Crucible!!

[Dani]

I am 12 years old and I'm auditioning for the part of Betty Parris in the play The Crucible in September. I have seen the whole script, and I need advice on how to play the part. During most scenes she's in, Betty is hysterical and delusional. She whines, screams, cries, and whimpers, among other things. I have tried saying the lines and can't really get into her mindset, no matter how hard I try. I know her character very well; I just can't find it in myself to BE her. I also want to learn how to make myself cry on cue -- it would be tremendously helpful on stage. Any advice? Have any of you played Betty before?