Helping A Ghost?

My name is Sonja. I was drawn to a missing person's case on the internet. She has been missing since 2011. I felt very compelled to help find this lady. When I did my psychic meditation I quickly discovered that she was murdered. She showed me that her body is buried next to a gravel/dirt pit in the woods in a shallow grave. For two months I meditated on the case and got the same results. A gravel pit and a shallow grave in the woods. I don't know if that is the only information that she knows or if I am asking the wrong questions. This is the first missing person case that I am working on. I mainly work on questions about love and careers with Tarot cards and my visions. I put the case on the back burner when I was not getting any new information and quit working on it for two months. Well three nights ago when I laid down to go to sleep when I closed my eyes she visited me and showed me the gravel pit and the shallow grave in the woods. It was as if she were saying, "don't give up on me". I told her I would start working on her case again, but she needed to show me something more if I was to help her. The next night the same thing. The gravel pit, but instead of the shallow grave I was looking up through the trees into the sky. I was wondering if there are any expert mediums that can tell me how to question her about her passing that I can get her location. I know she wants her body found and her killer brought to justice. I want so badly to help her, but I don't know what I'm doing wrong. Is this something my Spirit Guide can assist me with? Can he fill in the gaps of information that she cannot provide me? Psychic Investigation is something that I would like to go into and learn, but don't know how to ask the right questions.