First load up the game and go into any neighbourhood.
Once inside type in: ctrl, shift & C
A white box should appear at the top of the screen
Type in: Boolprop testingcheatsenabled true
The sims 2 is not in "debuging mode"
Go make your desired family, (Right now it will only let you have eight people)
Now move them in
Any extra people you want in this family need to be made,
E.G I want another female adult and a boy todler so i go out of the lot, make a new family with these two people. ( recomended: You name them as numbers (e.g- Mother-1, toddler-2) ((You will see why later, and the names can be changed))
Now move them into another lot
Go into the lot where you want your house to be when all your family are together.
Now that your in this lots press shift (the arrow underneath CAPS LOCK) and while holding it down click on the currently active sim (the sim with the plumbob/green diamond above their head)
You will get a whoel new list of options
(Dont worry, the old options will still be there as long as you dont hold down shift while clicking on the sim)
On the menu that comes up find "Spawn" (you may need to click more
Then click on Toombstone of L&D
a toombstone will appear next to your sim
(It can be deleted later)
Now click on the tombstone and fine "Add neighbour to family"
It takes a while but go through the list of names and find your sims. (This is why we recomended you call them numbers as if you call them a name like Jake there may be another sim called jake who is a townie and you may get a person you dont want, while nothing is called number that is sims 2 created)
gradually all the other family members you wanted are added to your family and there isnt really a limit to the number of people you have (Don't get too many or it gets hard to control)
Now you have your family of however many people you want, to change names, scroll down again...
Simple, make a sim you want the name of to be changed (the little picture fo them that makes them active)
Now click on the toombstone of L&D,
then choose "rename sim"
A small box appears,
now type in their name and it is permenantely changed! (unless you click the toombstone again)
You can now delete the toombstone if you want to.