I had a close childhood friend die when she was 15. I dreamt about her for months. The dreams were always the same she was happy and alive, everything was normal. At the end of the dream, I would always realize that she was really dead. She would then disappear and I would wake up.
I also had an extremely hard time dealing with her death. I think it effected so strongly because it was the first time I had to face my own mortality. Death was always something far removed. It was for the elderly and sick, not for someone jus like me.
Since a few years have passed since your friend died, you may have dreamed about her now because you subconsciously have a fear of forgetting her.
You will never forget her. Thirty four years later, I still think fondly about my friend.
Best wishes