I saw this on a new Nigeria christian forum, maybe your answer will help the girl. Will direct her here. She wrote:

I have never experienced so much sorrow in real life as I did in this dream. I vaguely remember this taking place in a living room. There was some grown adult beating his wife, and beating his kid. It wasn't just some random person but I felt like I knew him somehow. He was doing horrendous acts for absolutely no reason and I was witnessing this right in front of me. After seeing enough I got so mad that I beat him senseless and then he died. This is the part that's confusing and that really hit me hard. When he died I saw my three year old nephew come out of him. I saw the innocence of my three year old nephew walking around in that very person I killed in my dream. I broke and I started screaming in regret and crying so hard. I wanted to take back that action so bad! It was not just a regular cry, it was a cry I can't even put into words. The cry was one of the most painful and most sorrowful/regretful cries I have experienced. I was pleading everything even up to my own life to please take it back as I was watching my three year old nephew playing and exploring. I didn't care about anything except to take that action back and let him live. This dream was powerful because I have never experienced such pain before and it made me realize the innocence of humanity. Even though this man in my dream was masked with evil and did the most offensive and evil acts. I didn't see any of it when he died. All I saw was innocence, value, hope, love, and so much more. In a sense I felt evil because of my own action and it was killing me inside. I can't ever imagine coping with that sorrow and regret. Do you think this dream meant anything?

source : http://www.changeasoul.com/index.php?topic=16.msg19;topicseen#msg19

I think that the message is clear, hate sin not the sinner, in other word, we are all good inside even though we may look otherwise outside.

Meanwhile FTC

I honestly have no idea!

The mind is always thinking and active as long as u are in your conscious state,the only time the mind is not occupied by a thoughts is when u are sleeping,what the mind does @ that point is to replay ur previous thoughts as motion pictures we call dreams, in no particular order.it can replay ur thoughts or wishes of today or that of years back.85percent of our dreams are born thru the above process.nevertheless 15percent of dreams based on my christain faith are messages from God to those that has exceptional spiritual gifts,so my dear do not worry too much about ur dreams,they are just replayed thoughts in ur subconscious.

The dreamer should always mind his/her business. And not just jump into conclusion

Pray about it... Pray without ceasing.

See God reveals things to us through dreams for so many reasons: to warn us what devil is planning against us,how devil is planning to use us,even good things that are about to come and among other things. The good thing about our dreams is God has given us the power to change them.
The person has the power to change this,by this revelation, God has demonstrated that it is not his will.
Happy New Week.