Kent, I can't answer as a parent
I
CAN, being the parent of a daughter about the same age.
You did the right thing telling her to beat feet and get the hell outta Dodge...
She filed a police report, and the fuzz said, "well, uh.." because they don't have the resources to deal with every incident that happens when the population is swelled three-fold. [The Police] aren't interested in investigating an assault? Even the more reason for her to broom it out. What's it going to take for the Fuzz to get serious?
The "friends" stood there and watched it unfold? That piesses me off even more.
I know what I'd be doing; I wouldn't do it FOR her, but I'd have her back. We'd be in the County Prosecutor's Office swearing out a warrant ourselves. Who cares if it never goes anywhere; there's just something about wearing handcuffs that causes one to have an epiphany.