Background - PIL and step MIL have a daughter, DH's sister whop is 19, lives with boyfriend in their own place. SIL is (according to her mother) perfect, she is the best at her job, driving cooking cleaning, doesn't drink{hmm],never swears etc etc. MIl and step PIL live in the same town. MIL (not the mother of SIL) has just phoned and told me that a young trainee who works with her came into work today with a black eye and scratches all over her face. SIL had set upon her in a pub, because this girl (I'll call her Jane) is the daughter of SIL's best friends boyfriend. She (Jane) had been in the pub with her friend, and SIL came in with 10 of her friends and she started pulling this Janes hair and hitting her hard. MILs brother in law runs the pub and tried to stop it, at this point SIL's boyfriend hit the pub owner and started throwing glasses. Owner put them out and he and his sister offered to walk the girl home. When they got outside SIL and her friends were still hanging around and they started kicking and hitting and punching the girl again, and the pub owner said he was trying to get his mobile out to phone the police and SIL's boyfriend took it off him and stood on it.
DH is a bit blinkered when it comes to SIL, he has the same opinion of her as her parents, so do i tell him, or leave it. I am led to believe that the girl jane and the pub owner have notified the police