I read about how the game is supposed to allow aging to be throughout the neighborhood. Has anyone played this far into the game yet? Is there popups or is it where you are in the neighborhood and a sim you knew was a child last time you played him is now an adult?
Also I am wondering what the purpose is of being able to save each individual family asa a single game. But if you default to saving a game as Sunset Valley it is notr the neighborhood per se, but it is that family you last played. So you go in but then you go into main menu to try to get another afmily and it saves the last family.
Really I don't know what is the best way to keep things organized. Anyone got any ideas?

Each saved game is a separate instance of the neighbourhood.
Each instance of the neighbourhood has one designated active household.
A household is a number of sims, related or not, living on the same lot.
You play your active household.
The computer plays all other households in the neighbourhood at the same rate.
If you play your household for one sim day, the computer advances all the other households one sim day.
You can change the active household within an instance of the neighbourhood, but the computer will assume control of your previous active household and continue to advance it as your play your new active household.

For example:
You are playing John and Jane Smith. They have two lovely children, Mary and Martin. As long as they all live on one lot, you control them all. But Mary and Martin grow up and soon it is time for them to move out. When the kids move out, your one household becomes three households. Only one can be your active household. If you choose to stay with John and Jane, Mary and Martin will live lives outside your control. If you choose either Mary or Martin as your active household, John and Jane will grow old and eventually die. Again outside your control. The other sibling will also be outside your control.

When the kids move out you could Save As… instead of Save. Save as Mary. Save as Martin. Save as Elder Smiths. You now have three instances of the neighbourhood with your Smith family. You play as Martin in the Save As Martin instance. The game controls Mary. Later you play Mary in the Save As Mary instance. You start the game at the moment she moved out of her parents' house (assuming that's when you saved the game). The computer controls Martin. He will have a completely different experience than he did when you controlled him in the Save As Martin instance. They are separate games.

You can jump between households, but you can only play one at a time. If you want to follow both children in the same game, you could play one sim day with Martin as the active household. After a sim day of play you put him to bed and switch households at 2 a.m. Tuesday (for example). You pick up with Mary as the active sim at 2 a.m. Tuesday. The computer has played her for one day. Things beyond your control have happened. You play Mary for one sim day. Get her to bed and leave her household at 1:15 a.m. Wednesday. You resume playing Martin at 1:15 a.m. Wednesday. The computer has been in control of him for the day you were playing Mary.

This jumping style of play is possible, but there are many problems with it. The longer you leave sims in the computer's control, the more likely they are to spawn parthenogenetic babies or move out of town. Wishes, opportunities, and inventory vanish when you change active households. Lifetime achievement awards and unspent lifetime happiness points might also vanish. Modders are already working on these problems.

cool thanks for that. I actually figured out how to make it as it should work. I deleted all instances of the neighborhood and just have one. If I want to move to another family, I don't save. Click edit town, then switch active family and go play another family. Works that way the way I was thinking it should. No spawned babies yet, lol