The game really tries to lead the narrative of it being the combination of Charlotte and school that primarily lead to her being where she is. And yeah, she did live in a proverbial tower. She left the house to go to school, and other than that she was at home. At the beginning, she has very negligible social skills, and it's very easy to see. It even get to the point where she meets one cute guy, and is instantly obsessed with him and the fact that he'll be the best boyfriend and husband ever. Going so far as to get mad at people that even try to tell her otherwise. That's not something most people develop that have healthy social interactions. She doesn't have the experience of seeing men and women together, outside of her being bullied at school, so she has no basis of comparison to learn from.
How many scenes do we see where she was at school and leaves happy and cheerful? I can think of maybe one offhand and that was when the MC was directly involved and only because she went to get her stuff to do school at home. Further, in one school scene it bad that in once school scene the MC called Suzi to help, as he was having a hard time stopping himself from getting involved and he didn't want to hit teenage girls. Definitely not conducive to a healthy environment, especially when it's so blatant with no attempt to hide it and yet no authority figure(s) step in.
In Emma's personal life, she was over-sheltered and over-protected by Charlotte. Charlotte even says it later in the story, after the Zack incident. Outside of school, she had near zero social life and stayed at home. The one major scene when she does leave the house and goes to her friend's party, she ends up getting bullied and teased there.
