That was a majorly insensitive thing to say. It was all around what you felt, which is not wanting her to be sad all the time, and not really trying to understand what she felt. She lost someone important to her. Someone she used to talk to all the time, to laugh, to share secrets with. Once you lose that, there's just a hole in your life. Maybe try putting yourself in her shoes. You're upset because she hasn't even responded to you. Imagine how she feels.