@PatienceTheVirtue I don't have the pack so I don't go to the future either, however, to answer your question, yes and no.
I like my games to start off with a sandbox so I started bringing in roommates/ siblings at the beginning and let them plan it out. But I do set certain milestones for them (like I want my sim to get into her career first so that when she makes her babies she gets more money from her paid vacation... I'm a schemer)
But if my sims wish to go start their family off first then I let them take the wheel. I always have this plan in mind that when they finally get rich, I'll have a lazy sim who'll spend all the money on spa retreats until they're flat broke (but I don't have the heart to do it)
My questions
1. Do you guys use base game families, or do you fill your neighborhood with custom-made families?
2. Do you add families to your neighborhood for the sake of your current family (like, you want your sim to have a best friend or potential mate)
3. Do you force your sim to another even though they weren't attracted to the sim at the beginning?
4. Do you ever break up a family because your sim is attracted to a married sim?