I created a family in CAS: mom, dad, 2 teen girls and 1 teen boy. The teens are showing up as children to each of the adults (mom and dad) but the mom and dad are roomates. (wth?) I didn't realize ...
None of the modifyrelationship cheats or the ones to make friends works for me, still though. I'd like to try to get those working, guess I'll keep playing with it.