So, the viewpoint and main character in my novel is a character who had a very bad beginning. Born as a slave, she was torn from her parents and subjected to many horrors, few of which I elaborate on, before being taken to her latest owner, the daughter of a prominent lord. The daughter is exceedingly kind to everyone, and to the MC, she is the only character that the MC can consider a friend.
Her father, however, bought her for an ulterior motive. The MC looks very similar to her owner, to the point the two could often be confused. The father bought the MC so he could also act out some...desires. I won't elaborate too much, as I want to get to the punch line.
So, after a long time of this, the MC lashes out when her owner was trying to comfort her, and injures her severely. The MC didn't mean to cause harm, as she though the person who approached her was her abuser.
Anyhow, the MC begins to believe that those close to her will suffer harm, and after escaping and fleeing the fiefdom, she becomes a pickpocket and manages to stake out a living before being recruited as an adventurer.
Here's the thing, I want her to be somewhat antagonistic. She's a bit of a bully, but she never wants to actually harm anyone. She's desperate for an emotional connection, a bond that she can cherish, like the one the other characters are forming with each other. But before she starts healing, how do I give off the impression that she's pushing others away not because she wants to, but is trying to keep them safe rather than any other reason?