Sentiments

Repetitive behaviors or socials with a particular sim over time will gain sentiments. Traits and personalities also factor in too, or it feels like it to me. What is dad's sentiments towards her? Is he mean and nasty when they do interact, or just distant? The traits she has may make her needy and he's not giving her the attention she wants. The daughter wouldn't by any chance have the High Maintenance trait? Or some other trait that makes her crave attention?

Edit: I was just thinking, did the daughter have the clingy toddler trait? That may be where it came from.

I think - but am not sure - that negative sentiments can also be randomly assigned when the toddler's angry for any reason, like dislikes. Possibly also the same with child sims?

I had a Toddler holding a grudge against his mother. I think she was Potty Training him and he didn't want to so he got scolded for being defiant? It's been awhile. When he aged up, the grudge was gone. Yay.