sorry for bothering so often but i have some more questions
You're not bothering us. This is the whole purpose of this forum.
-now that Christopher is an elder , can i help him avoid dying soon ? , i want him to live ,at least to see his son turns into a teen!
Metro mentioned Ambrosia, but there's also Life Fruit to give him one extra day at a time, and there's the Death Flower. If he has a Death Flower in his inventory when he dies, Grim Reaper won't take him. Both of these methods require a high level of gardening skill.
-what skills can their son practice while being a "child" ? , he has the 'athletic" trait , how can i make him use this or where can he practice sports ?
Painting is a good one for children as they will gain actual skill points for it. The blocks table will give them a boost when they start the Handiness skill as teens or young adults. They can swim and work out, but I don't think it goes toward actual skill points. They can also learn the Writing skill on a computer for actual skill points. And they can learn the Fishing skill for actual skill points.
- if they had another baby , can i put the baby and the child in the same room ?
Technically, yes, they can both go in the same room. But as already mentioned, when the baby cries, it wakes up anyone else in the same room. They'll get a negative moodlet and will lose sleep, which will make them tired the next day.
-what happens for the children and the money if one of the parents die? and if both of them died !!?
As long as one of the children is at least a teenager, the household will simply continue when the parents die. You'll keep control of the ones remaining in the house and the money will still be there for you to use. If there's no teenager, the Social Worker will take the children and your game ends. I've never had that happen, personally.
Check the Guide for more help on parenting and raising children:
Surrounded by Family Walkthrough Baby Boomer Challenge Walkthrough Parenting Guide