SOOOO ANGRY!!!

I am so upset right now, and don't know what to do. Really there isn't anything I can do, which just makes me more upset. I won't explain what happened, but will leave it at this:
It is something extremely horrible that my brother's STEP daughter has done. Our family has always looked at this kid, as part of our family. Now, I hate her! She has stolen from us, lied, and now lying again to the point that will affect someones life. I don't know if this girl realizes the affect of her lie. This is something she will have to live with her entire life. Living with a lie, that affects someone the way this lie is going to is horrible.
I am just so angry. It shows you the importance of real family, and not outsiders that aren't truly family. Yes, she is a child, or a preteen, but she is a liar, and a thief. Part of the way this girl is, comes from her mother. I have always said "You live what you learn". I always have said that, because of my behavior and things I've learned growing up. Life hasn't always been easy, and it still isn't. But my family, who isn't perfect, has always been there for me. My father and I never really got along great, our personalities really clashed. Maybe I was just a lot like him. I have one hell of a temper, and don't let people walk on me, or mess with my family. I noticed, I do dwell on certain things too. I feel that I have become a good person, even with my flaws. Everyone out there has a flaw whether they admit to it or not.
With this situation going on right now, someone who is important to me is facing an uncertain future. I don't know what is going to happen, and I am afraid. I am angry, and scared. Fall was supposed to be great this year. My brother just arrived back home from Iraq, my youngest son will be having his first Halloween, and it was just supposed to be fun. Now, it's destroyed. All because a spoiled brat didn't get what she wanted for her birthday, so she came up with an outrageous lie. It is truly ashame how kids are becoming these days. If I were to lie like this as a kid, I would have been so guilt stricken. I would never have lied like this. How do you lie about something so serious? I am just in disbelief, I'm angry, OUTRAGED! I've rambled on enough. Hopefully I will have a good update to post later, not a bad one, but I am afraid that everything is heading for the bad.