@jake325
She doesn't have to combine all the families and houses into a single save. I suggested that simply because that is how I interpreted your original post and so, I told you what needs to be done to do that. She can play every family in a separate save with no problem if that is what she wants to do. All she has to do is as @jpkarlsen said, use the Load menu to select the save she wants to play. The Resume button can be used too, but all that does is take you to the last save played. If that's the one she wants to play when she starts the game, then use that button. If she wants to switch and play another family in another save, use the Load button, pick the save and play.
Keep in mind that you only play one family at the time. You can have dozens of families in the same save, all in different houses. While you play one family, the others just sort of sit there waiting for you to get around to playing them again. They will show up out in the worlds but depending on your game aging and other settings, they can be almost exactly as they were when you last played them the next time you go to play them, but your active family can interact and build friendships, romances, etc. with them. If you don't want that kind of play, then one family per save is the way to go. If you do want those interactions, then a single or a few saves is the way to go. It's entirely up to the player how they choose to play.
One thing about saves. The more saves you have, the longer it takes the selection panel to open when you use Load. And I have seen reports here where people had problems getting the list to display because they had so many. So, imo, it is probably best to keep the total number of active saves to no more than what you actually need.
Hope this helps.
