i had a dream and i was the ghost

Hi! I'm della... I had a dream about 2 nights ago, and I've a bit of trouble interpreting it...

So... There's 2 girls. They're sitting on the ground, looking up at me. The girl to my left is wearing a red polka dot dress. She has brown and wavy hair. The girl to my right has short blonde hair, that doesn't go past her shoulders. There are also two grandparents. They were ghosts. They were in front of the two girls, but they were standing. My perspective, was the grandparents perspective. So, I was basically, the grandparents. Both girls were just being happy. Then, the blonde girl (the girl to my/the grandparents right) turned to me/the grandparents, and said, "Do you want to tell her why you're here?" That's when I/the grandparents started screaming, "I hate you! You killed me! I want to murder you!" I actually felt the anger in my heart (like if I actually, physically, screamed). Then, I woke up, and I felt the anger in my heart.

I have just thought of what the dream could have meant, but I want to make sure with you...

My sister has recently injured me very badly (this happened about a month ago, and I actually had to go to the hospital). Now, she acts as if she never did anything... When my mom says she needs to be punished, my sister's just like, "Hey! I don't need to get punished! Why do I need to get punished!" Like, she actually forgot?!?

Anyway, it actually makes sense! I was in the perspective of the grandparents, who were mad that the little girl in the polka dot dress had killed them (or my sister hurting me, in my situation). The little girl was acting all happy, like she forgot about the whole thing (just like how my sister seemed to have forgot she ever hurt me)! Also, I get really mad when people forget about really bad things they've done, and act all innocent (which is like how the grandparents wanted her murdered, because they were mad)! I think my dream signifies that feeling... of not wanted people to be innocent when they aren't. I think it signifies, I shouldn't let my sister forget what she did.

Please Comment To Tell Me If I'm Right And What Your Interpretation Would Be