Eight people
I don't believe you can, but you could try marrying a sims within a family of eight.
I'm afraid you can't have more than eight sims in one household together at a time. I had this family once, when I had sims 2, and I had eight family members and I couldn't get pregnant or adopt any other babies.
No there isn't eight is the limit
Family friends are simply that, friends of your sims family.
Eight Sims can live on one lot.
Yes, your Sims can get married and have children together.
No, you cant remove any of them. The only way to remove a sims from the family though it to kill them.
8 sims maximum
Start a Family
You can have sims get married but they can not have children
No, Sims can not have relationships with anyone they are related to.