Symbolism

I dont ever really remember my dreams. As soon as I wake up I forget them. About a year ago I was having dreams about my little sister. I wasent living with her at the time she was in NY with my mom and I was here in NJ with my dad. In my dream I saw her crying and being yelled at a tall dark shadow. I remember running and locking herself in a room and laying in a bed crying her self to sleep.
I had that same dream about 3 times. At tue time I would only be able to see her on fridays through Sundays. Everytime I saw her she seemed sad. Like something was bothering her. I never asked her because she was never one to talk about her problems. After about a week I asked her what was wrong. Turned out that my step dad at the time use to yell at her and make her feel bad so she would run to her room  lock the door and just lay in bed.
I couldnt believe that my dream was showing me what was actually going on. To me my dream was ment for me to help out my sister. It was telling me a situation and to fix it before things got worse. My sister was going through a really hard time and I know for a fact if I haven't had those dreams I would have no clue on what was happening. My dream opened my eyes to see that I need to pay attention to little things. Im sure my sister was showing signs of being emotionaly abused I just didnt notice them.