Being able to have more than one sim adopt an offspring is essential, imo. It's so strange that it's an aspect that's been overlooked for this long. parents should be able to adopt a child TOGETHER, and on a slightly related note, yes, step-parents should be able to properly adopt their setp-kids and have a proper, specific relationship with them.
Personally, I don't mind adoption being "easy", as making babies in the game is also easier to accomplish than real life, so that at least seems relatively balanced in universe.
I do wish there was some way to make adoption more integrated with the world tho--like, not just having randomly generated sims as option to adopt, but maybe having any underage sim already living in the world without a guardian as options as well, and being able to give a baby up for adoption and then have another household adopt that child. In fact, as is I believe that if un unplayed household's adults die and leave an unattended child, the child just basically gets deleted (this was the biggest disappointment when it came to selling and giving pets up for adoption as well--they just disappear from the game, rather than going to live in another household). I use a setting on MCCC to make it so that child gets randomly adopted by another household, but ideally the game itself would have that feature rather than needing to rely on mods. In theory, it could be even better than that, with a player being able to designate some kind of "open to adopt" setting which would put them on a list to take in any child that gets left without a guardian, or something like that.
And I guess this might be harder given how simple sims family trees and dynamics are at the moment, but if they expand adoption in some of the ways suggested here, then one aspect that would be nice would be to have the ability for someone to have both biological and adoptive parents in their relationships and fmaily tree. Maybe some wouldn't know their biological parents, in which case there would effectively be no change, but for more "open" adoptions maybe that could be an option.
Also, this is a nitpick, and I know no one cares about whims cause they kind of have all sorts of problems with how they are now, but as someone who actually plays with whims and likes the idea of them and wishes they were better, I wish there was a whim to adopt a child as well as to try for for baby. I often follow whims and use them as cues to where my sim's story should go, and it's not uncommon that if they never have the whim to try for baby I just won't won't have them ever try for baby. But, that means it's easy for me to NEVER have my sims adopt--even tho I really like adoption as an option and story possibility--because there is no whim for it. So, this is another area where I wish they put more effort into bigger life whims, to give that option to help support a more whim heavy playstyle.
