The Bible doesn't answer all our questions about heaven -- but it tells us all we need to know.
And one of the things the Bible tells us about heaven is that it is far more glorious than anything we can possibly imagine. And as part of heaven's glory, our bodies will be changed, and we will become like Jesus Christ in His resurrected body. We won't be subject to the ills and ravages of old age, like we are now, for we will be changed! The Bible says, "what we will be has not yet been made known. But we know that when he (Christ) appears, we shall be like him, for we shall see him as he is" (1 John 3:2).
But the most important thing we need to know about heaven is that we will be in God's presence forever. Nothing evil will ever be able to touch us, for the devil and all he represents will be banished. Think of it: We -- and all our loved ones who have died in Christ -- will be safely in God's presence forever!
Do you have this hope? Does the hope you mention elsewhere in your letter that filled your grandmother also fill you? Make sure your life and your future are in Christ's hands -- and then live each day with one eye on the work God still has for you here, and the other eye on eternity.