I play it this way. This is just an example. I have 4 households -
1. Smith
2. Jones
3. Wilson
4. Evans
I switch the households every Monday 6am, step by step = first to fourth = Smith to Evans. When there is a YA sim who wants to live on his/her own, (s)he gets on the bottom of the list, that would be number five on my list. I move him/her out and keep playing with the original family, then on Monday I move to the next family on the list, and so on. The aging is on only for active family, but when I play with the first family I turn aging on for townies as well so they are not stucked in their age forever.