Interesting.
Our daughters friends were always welcome to call or email me, heck I still hear from some of them each week through FB and they have graduated from college now.
Back when I was a teen and went out with young men, there were times I spoke with the moms, even some that were not too thrilled with me. I had 2 strikes. 1. My parents were divorced! And my mom was pretty, smart and had a life.
2 I am Hispanic! Holy cow, looked like it too! Brown skin, long black hair.
They had no idea what to think of their Anglo sons dating a Mexican, you know how those girls get pregnant so easily... Yep, heard that from a dad of one of these guys..
I was used to a very open and honest home life. We could speak or ask about anything. My closest friends, their parents were the same, I could sit with any of them and have great conversations, and they seemed just fine with it. All of our parents told us, if we ever needed someone to speak with to please not be shy.
No hidden agenda, no manipulation, just teens who enjoy mature conversations and are used to speaking with all sorts of adults.
FYI, this girl is not crazy. She is depressed. That does not mean she is totally unstable, it means that like everyone else at some point in their lives, she is struggling with mental illness.
If you are worried about your son, seek help for him too. No one can make him do anything he does not want to, including you. So keep as much and any communication open, with no judgement, believe me, she knows who you are and that you do not care for her. Same with your son.