Does anybody know if you can?

Me and my girlfriend have different families, but when I go on mine, hers carries on in the background. She got annoyed because she missed one of the children's births haha.. is there a way you can change it so that her family doesnt carry on when im on mine?

As far as I know... Game settings->gameplay and there should be an option that says auto age (played sims) and auto age (unplayed sims) You can uncheck unplayed sims and it should take the aging off, unless you've actually played that household, in which case I guess you could try to go on hers and uncheck the played sims auto age and see if that works.

She's an active household.

* Simple fix, just go to Household Manager and click her family, you will see a white Plumbob in the bottom left, click that and her household should go into an inactive state.

Keep in mind this does NOT delete her household from the world!!! It only freezes her household's story progression. She can always go back and resume her gameplay.

If you're concerned about your household progressing without your consent, you should do the same for your household when she plays. You will have to repeat this procedure every time either of you play.

I think creating separate save files would be a better option for this, but as far as I know that's impossible once you've already placed both families in the same world.