One thing that got me was thinking what happened to loved ones when you redid time. While they are in some ways the same person, they are also vastly different

One thing that got me was thinking what happened to loved ones when you redid time. While they are in some ways the same person, they are also vastly different. Say you had a child who was 10, and you went 12 years into the past. You could potentially not have the child, but even if you did, they would be a completely different child. What if you went 9.5 years back. The same DNA, but life experiences would be different. Either way, when you go back, you are effectively forever losing your 10 year old child. But, does that hold if you only go back 10 minutes or 10 hours?