very pointedly doesn’t call her parents when toriel asks her to
her “defense” is putting her arms up in front of her face like shes blocking a punch, as opposed to something more fantastical, like Kris’s shield or ralsei’s cape
seemed genuinely surprised over getting her own bedroom
frequently seen eating whatever she can get her hands on (the alley milk, chalk, Kris’s shampoo??, etc) ((yes this could just be a bit but it feels more important than that)) + constantly seems to be hungry
^ adding onto that, one of the main ways she shows care for people is by getting them to eat (letting Lancer have the darkcandy, making sure ralsei has a slice of cake, baking the pie with toriel)
^^ adding onto that AGAIN, Ralsei is very careful to make sure Susie always has enough to eat in the dark world (offering to bake for her, filling her fridge)
doesn’t claim any of the houses/apartments in town to be hers, and anxiously asks Kris “we’re going to your house, right?” in ch.4
becomes super protective/attached the moment any adult shows her the slightest bit of care and doesn’t treat her like shes “bad” (toriel, old man, etc)
lightworld outfit appears to be pretty tattered, jeans have holes in them
always wanting to go back to the dark world
doesn’t seem like she’s gotten a lot of positive feedback before from teachers/adults (mentions that the old man is the only one whose taught her in a way that didn’t make her feel stupid)
acts violent/mean as a defense mechanism when shes upset (Lancer fight, Ralsei confrontation)
tells Kris that they “have a good mother”, + Toriel was the one who ended up comforting Susie when she was anxious about moving to a new town again, as opposed to her own goddamn parents???
mentions “one of the places I used to live”, implying shes been moved around a lot
doesn’t go to church, like we see many of the other kids doing with their parents/families
everything surrounding the piano incident— nobody stood up for her when she was told she wasn’t allowed to play (like you’d think a parent would), nobody was watching her/stopped her from coming back and smashing it, and nobody ever tried to teach her to play
tells kris that she hasn’t been to the diner since Toriel took her, presumably at least a year or so ago