No, I can assure you that your grandmother isn't bored in heaven. In heaven, we won't lack anything, and we won't ever be bored (like we sometimes are down here).
What will we do in heaven? Heaven is far greater than anything we can ever imagine but the Bible does give us some clues. For one thing, it tells us that God will have work for us to do in heaven. Just as the angels presently serve God, so we, too, will serve Him. The Bible says that "The throne of God and of the Lamb (Jesus) will be in the city, and his servants will serve him" (Revelation 22:3). Unlike here, however, we will never grow tired.
We also will worship God in heaven. Perhaps you find church boring but we won't be bored in heaven! Can you think of anything more exciting than seeing God face to face? The Bible says, "Then I heard every creature in heaven ... singing: 'To him who sits on the throne and to the Lamb be praise and honor and glory and power, for ever and ever!'" (Revelation 5:13).
But the most important question you can ask about heaven is this: Will you be going there some day? Will you see your grandmother again? You can know you are going to heaven by asking Jesus to come into your life today. It is the most important step you will ever take, for it will put you on the road to heaven.