Okay hm. 

Personality wise flaws could go as : She feels the need to help other people to a fault, she tends to not let people really inside and know her thoroughly and when she tries they push her away, she's also adventurous to a fault and for the majority of the time acts first and thinks later when it comes to an adventure or taking charge and it has gotten her in trouble more often than not. (Should I add more?) 

Reason Parents Snapped: I guess it could be that her father snapped, his alcoholism taking a slight turn for the worst, unable to handle the family life he took his aggressions out on her while her mother stood by and watched, too fearful and passive to do anything about it?