Yes, I don't know what, if anything, Adopt as Care Dependent actually does. Kids and teens will ask any adult household member for advice, whether you've done it or not. The school will call for random events, whether you've done it or not.
A tip that some may not have noticed: Infants will sleep wherever they run out of steam. One poster on another forum never bought cribs, they just let them zonk out wherever. The parent sim was broke and overwhelmed with their twin boys (and had made questionable choices leading up to them having twin boys) so it fit what was going on in the household.