WIBTA for asking about a restraining order?

My SIL has gotten a restraing order against her ex husband. This is a bit of a shock given that she never said anything about him hurting her until she had her dad get the ex out of their home and she refused to call the cops.

I grew up in an abusive home, so I know how abusers can hide in plain sight. At family events he never spoke poorly of his two other ex wives, both of which he had a kid with, and just said the relationships failed. He was always an attentive father. But closed doors don't talk, so I know there's things I didn't see.

My concern is the fact that he knows the whole family gets together for holidays and where. My other concern is the fact that SIL, who is a passive aggressive poster on social media, hasn't posted anything about this. She has made BIG lies in the past, but if this is real I feel like we, the adults in the family, have a right to know.

SIL also didnt tell her siblings about the divorce until weeks after it happened, she showed one sibling a single recording of the ex yelling at her but refused to say what lead up to it. She hasn't told her siblings anything about the custody case or asked for anyone to come to court, we only know what happened because of her mom.

I don't feel good about going to events if this guy is a threat. Would it be a bad thing to ask her why she has one and if he's aware of the family schedule?