I can guarantee you this didn’t happen in a vacuum. There were signs (abuse etc) before this.
I have no idea why anyone would even give the time of day to someone who doesn’t treat them nicely, much less allow someone to abuse them. Your self worth must be less than zero do to that.
both of your points are excellent.
to add to your “self worth” point, I would only add, its 99% how the child was raised. Even within my own extended family (ie people genetically, financially, geographically the same), I see vast differences in outcomes. Bad parenting and broken families transfers a world of problems onto children and thus, adults.