While we're on the subject of NPC service sims, I've noticed that their age transitions don't always work normally, at least without nraas SP. Babysitters and newspaper deliverers seem to stay listed as teens and children, respectively, well past their expected birthdays, until you invite them over (socially), at which point they show up in their new age category. I've actually had babysitters that stayed teens—listed in the relationship panel and on the menu for selecting invitees for a party—until suddenly, they were full adults, skipping the YA stage entirely.
This would just be a harmless (I think?) quirk, except that it comes with one other consequence: NPCs have a really hard time dying. I'm sure I could kill them off as efficiently as anyone else using MC, but without intervention, they refuse to go away. I don't mean that they stay the same age but rather that the game rolls their death days (with a notification just after midnight), and then 24 hours later, they're still alive. In my last save, I was told that Kate Pistachio (housekeeper) was about to die at least three separate times, days apart, and nothing ever happened to her. I suppose I could have invited her over, made her stay, and let Grimmy do his thing, but then I'd have had to deal with the urn or tombstone, and my household was complicated enough already. Is this normal? Or should I be doing something to cull the NPCs?
Also, are babies and toddlers supposed to age more quickly than my custom settings when they live in someone else's house? I always thought that this was due to each life stage starting at 1 day in rather than 0, as it would for my own household. But I just saw an infant age up to toddler the day after she was born, even though the infant stage is set for three days. It's not a huge deal; I'm just wondering if this is the way things are supposed to work.