Parenting is not easy. Daughters can be particularly tough.
I know, I am one, It has not been easy for my mom. Parenting skills vary, 
Parenting skills are learned along the way. It is something you develop and aren't born with.
There is a  Parent management training. They teach parents positive reinforcement methods
That is good to go through. I would attend that class for educational purposes alone.
Not only parents raise their children, There are a grandparent, a legal guardian, aunt, uncle or other family member, or a family friend.
That is true. I had a close friend raised by his aunt and uncle.
Orphaned or abandoned children receive parental care from non-parent blood relations. Your friend is lucky