DH didn’t tell me SiL was violent

There is still a stigma around men and domestic violence, add in the fact that it was familial, it is very likely that OP's husband finds it nearly impossible to talk about. Even to her. The trauma will be buried deep and dragging it all out will be very painful. I get that OP feels she should have been told before now but how would he start that conversation? I don't think I could bring up childhood trauma that easily. This needs to be handled very sensitively and with as little accusation as possible.

@LionME I’m sorry you have had experiences which have led to a diagnosis of complex PTSD. I’m sure this w I’ll make you even more aware that every persons trauma, how they experience that trauma, and how they react to that experience is individual to them at that time and can change. A constant is how unhelpful it is to generalise, make assumptions or ask for justifications.
Ihope you receive the time, compassion and care to help you move forward in a way you value.

Fully agree @idontunderstandyou

It was part of my very first answer to you.

@LongDarkTeatime im a victim of childhood abuse. Currently being diagnosed with c-PTSD because of that.
I think I know about abuse too.

And I still think that struggling to talk about childhood is fair enough. I don’t agree about not mentioning the violent behaviour in recent years.

Well that depends which time me point you’re referring to. Obviously you are familiar with how long victims of abuse take to recognise then fully understand their experiences. So are you talking about when I found the courage to distance myself from my abuser, when I began to understand it was unacceptable behaviour, when I began to understand it was abuse, when I found the courage to label it as abuse out loud, when I found the courage to name it over and over and over again when challenged, or just now when you asked the overly simplistic question?
Yes, at one of those points I did talk to my partner, but after I’d protected DC because hypervigilance makes you act first.

Your poor DH 😢 I understand your mothering instinct is more important than anything but please listen to him before leading with anger

@LongDarkTeatime but have you talk to your dh about it or have you hidden it?

It’s one thing to be like an hawk and have agreed with the other parent that it’s an adequate response. It’s another to take the decision and not involve your partner. They’re allowed to make a different risk assessment and expect a discussion around it.

Whatever it was, she was arrested for a violent incident in the last few years.

Would you really hide from your partner that a close family member is violent, enough to be arrested? I mean the bar is quite high for that…..

Just that incident, wo the childhood stuff, is an issue imo.

@idontunderstandyou your husband is a victim of abuse. Please don’t assume he hasn’t taken steps to keep your DC safe. He is likely to be hyper vigilant in every situation.
My nearly 10yrs older sister abused me and her behaviour has continued into adulthood. Believe me, this type of sibling abuse is regularly minimised as ‘sibling rivalry’ and ‘high jinx’ - yes I have lifelong scars too. Your husband is likely to have lots of internal conflict about how to view her behaviour and shame at being a victim. Even when you distance yourself from a sibling abuser you have to continually justify it to family and society. It’s damned hard to justify/ re-live over and over and over and over. The shame just piles up.
Please, please don’t be annoyed or angry with him. Just go to him with open arms and empathy so you can help him move forward together. Remember you are the one with all the power in this situation so please use it kindly.

Spending time with her, as what, she is their mentor, a confident, a role model? Any of those things? Doesnt sound like it

Sounds as if perhaps she visits or they visit her or other family and they sit around, perhaps she talks to them, plays with them, cuddles them, but they're not alone with her. OP hasnt said she has been aggressive or inappropriate with them (or OP), they sit on a sofa, at the table, out at a restaurant or whereever they are going.

When you say 'trust with my children' what does this mean, is she taking them away on holiday or something?

It is, because her children are spending time with this woman.

When I was little I accidentally knocked over the bike of a lady who worked for my parents. She got in my face, held up a finger and said nastily “If I find a scratch on this I’m going to take this fingernail and scrape it down your cheek and make you bleed.”

I burst into tears. My mum came over and the woman switched to kind and polite, saying to me so kindly “Oh it’s okay! It’s just a bike, it doesn’t matter!”

I was too distraught to explain what had happened, it was horrifying for little me. I just felt embarrassed and kept it to myself because I didn’t want the lady to do anything like that again.

All that to say, I wouldn’t trust this person with my children at all.

Apart from being rude, she hasnt been a risk to you and the kids though has she?

So yes its not nice to think about the relationship they once had and him being harmed by her, but thats about it in terms of 'your business'. Theres no suggestion your kids are going to be alone with her, so its not really relevant to them unless one of them says Im going round Aunties house today. Which sounds unlikely

You can work yourself up about the sister being in your house around your children, or you can not work yourself up because she was never left alone with them, nothing’s ever happened and your DC are fine. It sounds like you’re inclined to do the former, but it seems unproductive and needlessly panicked, and feels much better to presume your DH and the father of your 4 dc hasn’t deliberately connived to lie to you and put your children at harm. Why not give him the benefit of the doubt and approach any conversation with about this with love and care, not assuming the worst?

I'm not the same person I was as a teen. Do you know what she was arrested for in the last few years?

It’s a very complicated issue for your DH. He is probably balancing his own needs to normalise relationships in his family and not pass on uncomfortable feelings of alienation to his children.

He may not feel he has enough support within the family to banish her, and it sounds like there are other victims too whose feeling may weigh on him. And if she was violent as a child, it’s quite possible someone was violent with her - even someone else in the family so the sense of her responsibility might be diluted.

Family abuse is always like this, it lasts through the generations and impacts everyone and every occasion that the family gets together.

Your children’s safety is important of course, but if they are not exposed, your DH’s emotional safety is paramount. He doesn’t have to tell everyone about his experience. Often the act of telling people over a lifetime is so re-victimising, and so pointless in terms of any gains, that people prefer not to.

I get completely why you’re upset with him. But from his perspective, he has probably been encouraged heavily to get over everything she’s done “because she’s family”. If she’s always been a violent, quick to anger bully and he’s known no different, this was normal for him. She’s 10 years older than he is so this behaviour was I’m guessing already established by the time he was born. It’s honestly shocking what some families let slide because it’s “just that person's way” and they’re related.

I would talk to him about it, let him talk about her and what she’s done if he will, and both agree that you will never, ever leave her alone with your children again. I really hope he will have a conversation with you and not bury this shit. It needs to come out.

It happened back in their teens. It obviously isn't/wasn't good it happened but your dh doesn't see it as a current issue that needs raised you should respect that.

If nothing physical has happened in adulthood when teen hormones/rashness are now out of the equation, I think your are being OTT to be angry about it or considering causing issues in his family over it by considering not letting the kids anywhere near her.

My dbro lamped me a couple of time when we were kids/teens, I am confident it is not something that will happen again, we just wound each other up. I've never mentioned it to dh, not that it is a secret of any kind, it is just irrelevant childhood stuff that has never come up in conversation.

If he hasn't left the children alone with her then YABU.

Don't make this all about you.

Do not approach him in anger. Talk with him about what you heard, but in the calm way that you'd use with someone who was a victim.

DO NOT leap to demanding that the children are never in her company again. They have never been left alone with her, nor will they be. Don't re-traumatise your DH that way. You don't yet have his version or his perspective, and how he deals with family life now. Please don't turn it into a drama. Your children are fine, there is no imminent danger to them at all. It sounds as though he's managing things in his own way and he keeps them safe by being there.