What if a minor threatens to kill me?

A minor (16 to be exact) threatened to "murder" me in my sleep with a "rusty machete". These are the exact words she used. It was in a Facebook message. I'm 18. Of course it takes a LOT to get a minor in trouble, but I'm pregnant, and she is perfectly aware of this. She is technically threatening me and my unborn child, is she not? If I were a minor I'd probably have better luck, but my baby's a minor. Should I do something about this or would it be a waste of time? I know she's most likely not going to do anything, but she's caused me so many problems as of late and it's put a lot of stress on me and therefore my unborn son. Just because someone is 16 doesn't mean they should be allowed to threaten people. Would I have any more luck with a lawyer?