The Bible doesn’t answer all our questions about Heaven—because Heaven is far more wonderful and glorious than our limited minds can fully grasp! Someday we’ll see Heaven in all of its glory—but in the meantime (as the Bible says), “we see only a reflection as in a mirror. … Now I know in part; then I shall know fully” (1 Corinthians 13:12).
But the Bible does tell us a great deal about Heaven—and everything it tells us should make us want to go there! For example, it tells us that in Heaven all the burdens and disappointments and evils of this life will be banished—and they will never trouble us again. As your grandmother grew older, she could no longer do everything she once did, and (as you say), her health began to fade. But now those can no longer touch her. The Bible says, “There will be no more death or mourning or crying or pain, for the old order of things has passed away” (Revelation 21:4).
The greatest truth about Heaven, however, is that we will be safely in God’s presence forever. We can barely imagine it—but someday we will see Christ in all of His glory, and then we’ll fully understand the depths of His love and His sacrifice for us. The Bible says, “the glory of God gives it light, and the Lamb is its lamp” (Revelation 21:23).