Yes, I believe God occasionally does grant a glimpse of heaven's glory to some before they die. My own mother seemed to have experienced this briefly as her own death approached. Perhaps this is what happened to your aunt.
I have sometimes wondered why God grants this to some people but not to others–and I don't honestly have an answer. But I do know that whenever believers die, we can be sure they are taken safely into God's presence–whether they experienced any sense of heaven's glory in advance or not. Why is this? The reason is because of what Christ did for us. By His death and resurrection, Christ conquered sin and death–and because of that, we don't need to fear death any longer. In Christ "we are more than conquerors through him who loved us" (Romans 8:37).
The Bible says God "will command his angels concerning you to guard you in all your ways" (Psalm 91:11)–even at death. The words my mother taught me many years ago from Psalm 23 still give me great comfort: "Yea, though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me; thy rod and thy staff they comfort me" (Psalm 23:4, KJV).
Is your hope in Christ? As we approach this Easter season, stop to reflect on Christ and what He did for you–and then put your faith and trust in Him alone for your salvation.