Her mother was shot in front of her when she was a child, her brother abandoned her out of frustration, and the man who took her in as his daughter died without ever getting to see her become who she is today.
It solely depends on writing skill. My sona has gruesome past and future won't be any better. He is rather positive character but has his moments. Is he a villain? Well technically yes, he is a warlord. This for his people he is a hero and for everyone else he is a monster and so the same goes for my other characters. Well written bad backstory can make character more realistic.I tend to avoid gruesome pasts on my characters to make sure they don't come off as edgy, however some character do have more unfortunate backgrounds than most others I make, usually those who play roles as "villains" or antagonists of the story line.