Sharon, death is something that we never get use to because it was never suppose to happen, and it would not have if Adam and Eve had not sinned. Remember, God gave Adam the command not to eat from the tree of life, that in the day that Adam ate from it he would positively die. But Adam listened to his wife, rather than God, and they lost everlasting life for themselves, and their offspring, which has trickled down to us.
But God did not give up on His plan for mankind to live forever, right in the garden the first prophecy was spoken. Please, Sharon, open your Bible to Genesis chapter 3 and start reading at verse 1-20. But notice at verse 15 is where the prophecy was pronounced.
God said that the serpent would be bruised in the head (meaning death) and the woman's seed (meaning Jesus) would be bruised in the heel. So when Jesus came to earth, died, and was resurrected , this was his bruising in the heel, also at Armageddon, when Satan is thrown into the abyss this will be the death of him.
I guess you are wondering, where am I going with this, well, Sharon, after Armageddon is over, and the dust has settled. Jesus is going to start resurrecting ones that are sleeping in death, and your brother and daughter, could very well be among them.
At John 5:28,29 Jesus said " Do not marvel at this, because the hour is coming in which all those in the memorial tombs will hear his voice and come out, those who did good things to a resurrection of life,and those who practiced vile things to a resurrection of judgment"
And remember how Jesus referred to Lazarus's death, Jesus first said to his disciples that Lazarus was sleeping, then Jesus recognized that his disciples did not understand, so he told them that Lazarus was dead. Sharon, please read that account at John 11:1-44