Yeah, it bugs me that it's all so uniform. Always +3 sad for two days, no matter what sim and what relationship they had. A casual friend shoudn't be as long as a close family member, it's very annoying.
Just today, I logged into a household to find the family's toddler was in mourning. Turns out, their nanny had died. None of the rest of the family seemed to care--guess they weren't that close with the nanny. And I could kinda get with that storywise. But then, it went on for two days, and man that is forever for a toddler. I've been playing on long (longer than long actually, thanks to MCCC--only way I can handle the number of households I'm at now) but if I were playing normal? 2 days is almost a 3rd of a toddler life stage. That's...a lot. So, I think the mourning should be adjusted by life stage as well as relationship. Personality too, ideally--so a gloomy sim would stay sad longer than a cheerful one, for instance, but that's maybe getting too picky. But I think the shorter life stages should have shorter mourning times, just ofr practicalities sake.
(Also, how did the toddler get a death notification in the first place? They couldn't have "witnessed" the death since I wasn't playing them, and toddlers don't have phones????)