I had two toddlers with the charmer trait age up via birthday cake, and they still get the negative moodlet toddler charmers get if they go without talking to people for a long period of time. It's a sad +1 called "Where is everyone?"
The annoying thing is, nothing makes it go away except a moodlet solver potion. As toddlers, just talking to someone would make it go away. I've had my children talk to people, get comforted, and cry it out in bed, but nothing removes the +1 sad except the moodlet solver potion you buy with aspiration points.
I even tried the "remove all buffs" cheat, and it removed every buff but the sad moodlet.
I also saw one of my kids get a "stranger danger" tense moodlet after playing with her talking llama toy. I've never seen that before, but I think that's a toddler-only moodlet too?
Is there any way to remove the sad moodlet? Neither of my kids still have the charmer trait in their profiles, but I guess it's still in there somewhere.
Added screenshots of one of the children with the moodlet so it's clear which one I'm talking about.