I don't know what to do about my grandmother dying?

My grandma's cancer is everywhere. She's in a Hospice right now, and I spoke to her today. She didn't say anything back to me. I told her about how much I love her, some of our memories and I sang to her. She's going to die very soon. When my aunt said goodbye to her, my grandma said "I love you" but she didn't say it to me. I just don't know what to do, she's so important to me. How can I prepare for when she really dies?