All good questions. I think you are conflating stages of life together. We are on earth now. Our spiritual body is joined with our physical body. At death, the body and spirit separate. The body to the grave and the spirit to either paradise or spirit prison (of evil doers) 1Peter 3:19-20. Our spirits in paradise will reunite with our ancestors and I believe (my opinion) our spirits will look like we did while on earth prior to dying except whole. After all, the spirit isn't what has cancer or a missing limb.
Let's also remember in John 3:13, it says, "No man hath ascended up to heaven, but he that came down from heaven, even the Son of man which is in heaven." We then first came down from heaven to earth meaning our spirit bodies came down and joined with our physical body. If not, we could not ascend in the resurrection with Christ because he did. So, when we die and return to paradise, we will see those we knew before coming down. A true happy reunion in paradise. Not so in Spirit Prison as much. Al though, I think there will be communication between those in the two arenas because Christ went from paradise to spirit prison and I think we will assist him in teaching and preaching to all those who did not have the opportunity to here the Word of God if we get to go to paradise. And, at some point in time, we will be resurrected as the Bible so states. Our bodies will be made incorruptible. Some more glorious than others 1Corinthians chapter 15. The earthly age that we will be? Unknown but not a hair on our heads will be lost. Nor will it matter as there will be no more vanity.
There is another part of your questioning that seems to belong more during the Millennium. The 1,000 years or so in which Satan will be bound and the Lord's work can be finished. People won't die during that period. There may be births as well. During that time period, perhaps those who didn't have the opportunity to be tested will be raised by goodly parents still on the earth. But, at the end of the 1,000 years, Satan will be loosed and the children will have the opportunity to choose for themselves good or evil. And, shortly after, the battle of God and Magog will happen and then the earth will be raised to its Celestial Glory. The only other thing is that children who died prior to the Millennium before they were old enough to be held accountable for their sins will be resurrected to the highest glory of all. They were they with Gabriel who ushered out Lucifer and his fallen angels from heaven promised not to be harmed spiritually by Lucifer while here on earth.