Please help me get me head around DSC's sibling relationship/ DHs role

[KellyanneConway]

I have 2 DSC, DSD14, DSS,12. Live with us since they were 5&7 due to their mum's mental health/ alcohol issues. DSD suffered the brunt of the effects of her mum's problems - DSS does not remember much as too young/ asleep (I wonder if this is a contributing factor to their current relationship?).

DH has been at stay at home dad since DSC were very young & his ex became ill (fortunately he has an ok income through renting out some properties he inherited). I work full time and have 2 older adult children who no longer live at home.

7 years on and DSCs mum has now been through rehab, sober for maybe 3 years and is now a single mum to a toddler. DSCs resumed regular contact with her when she was pregnant. She has been monitored by SS since her pregnancy due to her being in rehab directly before getting pregnant and DH is confident that she has remained sober in this time.

I have always got on well with both DSC, they treat me and my dcs with kindness and respect (much more so than they do each other and their dad) and act appropriately for their age when with us. DH does the bulk of domestic/ parenting stuff which makes things easier.
It is their relationship with each other and to a lesser extent, interaction with DH that has become extremely challenging. They cannot co-exist comfortably and are extremely immature when in each other's company. This has got worse as they have got older and is now a real problem. They interact by either winding each other up resulting in screaming , hitting and kicking or when they are getting on (for a few minutes at a time max) its loud, performative, attention seeking, characterized by screaming, screeching, shouting, playfighting, throwing things & pulling people apart (celebrities, people at school, internet randoms), calling people names & laughing at them. Because they are a nightmare together we cant leave them alone in the house or anywhere else other than their mums - even she went through a phase of having only having one of them at time.

Alone and especially when my DH is not about they are lovely, really polite, pleasant and I do love them & have some great times with them. I just cant bear being in the house with them and DH at the same time any longer.

This weekend while they were at their mum's it all culminated in much bigger, stronger DSD laying into younger DSS. He now has 2 black eyes. I thought that this might be a catalyst for real intervention (maybe counselling) as that level of violence is totally unacceptable. DH has grounded her for a month but apparently there are mitigating circumstances - "he wound her up" and she's still doing her hobbies just cant go to friend's houses. So its actually a semi-grounded approach and not much of an intervention at all.

I was working upstairs earlier listening to them shrieking in the garden with MIL's dog we are looking after looking terrified as they kicked a football at him then let him chase our cat. Cue lots of very loud whooping and screeching. Then on the way back in DSD ran ahead and slammed the back door in DSS's face. So it looks like everything is pretty much back to how it was.

I don't think this is normal? I argued with my siblings, my DCs argued at bit when they were younger, friends, cousins etc the same and we could be loud sometimes - but there were also lots of times where we were just indifferent to each other. Just able to potter along and take no notice of each other. I have never come across sibling interaction this extreme before. Can anyone please help me unpick what is going on and respond appropriately to the situation?

Counselling for DSD sounds appropriate as she's been through the brunt of it and is seemingly acting out.

Also just a thought but did mum drink during pregnancy with them? Some of the behaviour sounds pretty extreme. If not due to developmental issues, then lack of boundaries could be to blame. Dh's response sounds weak to the physical bullying by his daughter.

Sorry for brief reply.

Yes she did drink during pregnancy according to DH. But the extreme behaviour is only when DSS is around. Both doing fine at school hobbies, friendships so if some long lasting physical effect would it not be there across contexts? I will read up on it though, thanks for the suggestions.

Counselling would be my first suggestion - not quite the same, but my older siblings really resent the fact I escaped our parents abuse much younger than them (though took them years to understand/admit it) and sounds like your DSD could be similar.

The other thing is that if they are so much worse with your DH around then why is that? Are they competing for his attention? Testing him to see if he'll abandon them too?

Counselling for the children individually and family couselling for you all could be really worthwhile.

The fact that DSS ended up with a black eye from DSD should have been enough for your H to insist on outside help.

Minimum should be regular therapy for DSD, but it sounds like that as well as family therapy would be helpful.

Has your H always let her get away with violence?

They are crying out for family therapy.

I agree with all of this. DH has now asked the school for help. I encouraged him to do it as I thought DSS's black eyes would be flagged as a safeguarding issue (it was not though). The pastoral lead is apparently going to do some kind of work with the two of them. The problem in the past when trying to access services (when we found out what DSD had been through) has been that, because DSC are doing reasonably well in school and get on well with other peers and adults they were low priority and services were swamped.

@Bookaholic73, DH pulls her up on her behaviour constantly. DSS minimises and tells him its ok, she goes to her room for a bit, gets grounded for a few days and we are back in the same dysfunctional cycle soon after.

@JustLyra I am not sure why they are worse with DH. They also behave in that intense way with their grandparents, uncle and Mum too. They are less intense with each other when me, my DC or anyone else is around so its just an odd dynamic with a constant cycle of immature/ hyper interaction followed by fighting that seems to be kind of accepted by DH & his family, even though they obviously don't like it and tell them to stop (the fighting anyway). DH, his family and DSCs are all extrovert types, where as me and my family are much more self-contained. I'm not sure if that is relevant. I just can't unpick the dynamic at all. It's exhausting.

I wonder if it comes from deep insecurities. They are pushing the other away as hard as possible so they don't get abandoned by them, it gives them some control.

DC that are adopted are often horrifically behaved towards carers/parents they adore and are adored by because they test those boundaries to the limit. They are also afraid of living their parents/siblings in case they leave them too and want to keep them at an emotional distance.

It seems like attachment issues but they do need professional help as a family, all three of them. Would your DH be willing to do that?

DH says he is willing to do counselling, or rather get some support for DSD but then doesn't action it. I think it is because he doesn't want to have the conversation with her, which is why I was hoping that the punch in the face would be a catalyst, a "way in" to having those conversations. I'm going to ask him later tonight if the school has been back in touch and, if they haven't started to implement something, suggest again that he pays someone to facilitate the support for DSD.