That's a life lesson she rightfully learned by dealing with a grown man.
If it was a boy her age, it might not have resulted in death and not having her mother at home. And she needs to understand that going forward in life. I ain't saying throw the girl in jail. But whoever is the next responsible adult that has to deal with her needs to place emphasis on everything that transpire and let her know... She is not to be sneaking anybody in any more houses she resides in.
Like think if this was your niece, and your sister went to jail. And she had to come into your home? Would you not be more diligent in paying attention to how she moves and if she's still in the business of trying to talk to grown ass men??
Or would you just give her the benefit of doubt and not bother?
Yeah i would be more diligent but thats said with the hindsight of what's already happened. So it's easier to say "see look what happened last time you did this." Even beforehand you can emphasize the fact that bad actions= bad consequences every day. But at 13 most of them not really thinking that breaking one of your parents rules will result in somebody dying.