The Funeral

This is on the borderline of a ghost story and paranormal, I guess...

Before anyone had a hunch that Grandma was about to pass away, I had this dream. Although I haven't visited Grandma for a while, we talked on the phone alot. I always wanted to visit her but I never had the money to do so. This dream was very vivid and very real:
I walked into this church, and it was empty except for this casket. I naturally wondered who it was so I walked up to it. There, lying in a casket was Grandma. I remembered thinking how nice it was to see her again, and then thought to myself that this dream wasn't real because it's not possible for me to be there in the first place. I woke up and had a very strong feeling that it was a premonition that she wasn't going to last long. Within a month, she passed away from cancer. She was told it was the flu until she wound up in the hospital from it. This is my big question: I wondered what made me dream of this. Did some spirit tried to tell me something? I always thought to myself (after hearing ghost stories) that if some ghost wants to speak to me, let them tell me in my dreams. I wondered if some soul sent me a message...Anycase, thanks to this dream, I was able to tell her goodbye before anyone else did.