To think Dsis is overeacting after SS hit niece?

I agree! 10 year old sounds like a brat.

There's got to be a fair difference unless she's a ridiculouslyntall 10 yr old also he's a 15 yr old boy unable to control his temper to the point of hitting a much younger girl. You're under reacting. I'd be seeking help for him, I'd be sending dp home with him too, he can't cope with this holiday, he needs to be somewhere he can regulate himself. .

Honestly he really could have killed her
At 5"5 he is only slightly shorter than average for his age
He has atleast 50% more muscle mass than her
Males can punch with 160% more force than females.
He will have bones about 15% denser than her meaning fracturing her skull would be easier than a boys.
I highly doubt that a 10 year old girl is nearly 5"5 as the average hight of fully grown women is 5"3 in the uk.

These are just some stats that show the difference between the average 15 year old boy vs a 10 year old girl.
You can not minimise how bad his actions are he hit a little girl .
Oh and btw at 15 hes already stronger than you

Not even a little
But you dont know when to stop.
I rest my case.

and still no accountability. Still blaming everyone else. And defending abuse. Lots of us had terrible childhoods with abuse. Hidden behind facades of respectability and private schools.
I take accountability for my behaviour when it crosses the line even though its due to my trauma. I dont ever blame anyone else "for my winding me up " thats ridiculous.

And i have never ever physically hurt anyone. Funny that.
Bet this poor little 15yr old wouldn't have smacked an older boy in the face for "winding him up". But a 10yr old girl. Fair game

Did your Mum used to snatch things away from your dad and damage them and then follow your dad as he tried to leave the room ridiculing him? Did she deliberately taunt him?

An adult asking his child to intervene we he was violent is NOTHING like a traumatised child quite literally backed into a corner.

Was it acceptable behaviour? No it wasn’t, but it doesn’t seem to me like the two circumstances are comparable.

My teenage niece lost her temper with her hair straighteners the other day when she couldn’t get her curls right. She threw them across the room. Said some bad words too. Ideal behaviour? Nope. Prone to violence? Probably not…

Is it just because he is an abuse survivor that you feel you can predict the trajectory of his behaviour based on such a small amount of information?

Poor little you.

I do think you parented this one badly op. You could see her winding him up, you said stop it a few times and that's all. He walked off, she followed, you know he's likely to escalate when he's wound up but you put feeding your child over protecting the other two - her from him and him from himself.

You get up, you go over, and you stand between them. You tell niece to leave X alone or she'll have Y consequence. Yo u give him the space to leave and you block her following. If she does, you follow her and block her from his room.

Basically, you be the adult

No. This is another adult refusing to understand that their precious female child provoked. And wasn't parented properly by their parent. In fact almost encouraged by the sounds of it. The stepson has been receiving support but clearly not from all of the family. Best sister and niece stay well away, whilst step dad and step mum do their best to help this teenager.

The whole thing sound bonkers. Both children are to blame. Sound like holiday from hell if you ask me. Your and her family shouldn’t be on holiday together.

And yet the first thing you do is hurl abuse at me.
Right.

Oh piss off.

I was temporarily removed from mainstream education prior to secondary school because of the violent outbursts I'd have due to the emotional dysregulation/poor impulse control linked to having severe ADHD and dyspraxia.

I'm a fully functioning responsible adult with a good job nowadays but had somebody wound me up and then deliberately damaged my stuff I'd probs have struggled to walk away like he did. Had somebody followed me and got in my personal space I'd have probably punched them in the face.

What he did was wrong but he likely can't control his emotions. He needs managed, whether that constitutes stepping in or preventing him from being in that situation in the first place. A teenage victim of abuse struggling to control his emotions and trying to remove himself from a volatile situation needs to not be backed into a corner while the adults stand by and watch.

I've done far worse. I stabbed a metal technical pencil all the way through another child's hand and threw a metal ruler at a boy splitting his lip and breaking a front tooth. Also hit a much older boy over the head with one of those heavy desktop hole punches. Every single situation involved me minding my own business and other kids relentlessly trying to get a rise out of me. The situation should never have been allowed to escalate.

Your poor SS. Whether or not he is a blood relative or has a piece of paper saying you adopted him is irrelevant, as he is being brought up in your home as your child and not as a thing that can be handed back when the going gets hard.
It sounds like you and your DH are working hard to get him the support and help that he needs and that he is willingly participating in that. That's no small feat and anyone who has not walked in your shoes really has no idea how difficult that is.

It sounds like you might need to focus a little more on keeping him away from overstimulating situations (like arcades or with other annoying, poorly behaved children) until he is better equipped to handle them. As an aside, has he been assessed for developmental delays or autism or ADHD or mood disorders or learning differences? (As the parent of DC's (and SDC's) who had some of these diagnoses, I can say that understanding the underlying issues is crucial to helping your child develop coping methods.)
(It also sounds like your niece needs some help in understanding how to manage her own moods and desires, but that's not your journey to take.)

I think you’re getting a hard time on here OP. It’s clearly an emotive topic. 10 year olds are deemed old enough to be criminally responsible for their behaviour so I feel like whilst he was inappropriate (which you clearly know) she also should know better.
She must be 11 in the next couple of weeks if she is going to secondary school in September. I haven’t read all of the responses ;however, I can see that he has additional needs and is accessing support. I think empathy seems to only be going one way at the moment which is sad to see.

Downplaying this or excusing this because of 'trauma' won't help your SS long term. He needs therapy or anger management. He could end up a criminal/domestic abuser if you don't nip it in the bud

You should have taken her by the hand and removed your niece from the situation. As the adult in the situation you handled it really poorly. Yes you may have been feeding the baby but it would have taken seconds to do this

Spoken like a true abuser.
'She just wouldnt stop your honour'.
Shame on you..

You should still discuss and acknowledge the behaviour. Otherwise your DD will believe you are happy with her behaving in that manner and continue to do so.

Oh dear...this is very confused. I've worked in courts, victim support, witness service, probation etc..so can confidently say you are wrong.

Personally, my father used to ask me to intervene and stop him if he lost his temper and beat my Mum.

People have a tipping point...behaviour before they move to violence is irrelevant...taking violent action ...IS PROOF of 'violent tendencies'. Though how that has come up in relation to this scenario I am unclear

Being angry "at" a machine is further evidence of worrying dysregulation issues.

Under 16s it isn’t seen as domestic abuse in statutory legal definitions.

Hes 15.

The other child’s behaviours were also abusive.

Let’s stop throwing around Domestic Abuse and male versus females.

Let’s keep this to what’s needed. A 15 year old boy in need of support and guidance after an abusive childhood. That’s not to say consequences to hitting her aren’t needed but he shouldn’t be criminalised and shunned.

@PapaSteel you might find better support in foster carers /kinship care part of Mumsnet.

People who understand what’s needed rather than phrases like what’s being given by people who just don’t get it.

Your niece shouldn't have been winding your step-son up and absolutely should have backed off when an adult told her to do so. However, your step-son is 15, regardless of any trauma he may be experiencing, hitting a young girl, no matter how annoying she may be, is unacceptable. He's not stupid, he knows right from wrong, therefore he knows he shouldn't be hitting other people.

Your niece needs to be held to account for the part that she played, because she's definitely not blameless. If your step-son is willing and capable of hitting a 10 year old girl, then he's capable of hitting anyone. He needs therapy urgently.

Unfortunately, if your step-son starts raising his hand to others, then yes, you may have the police knocking on the door.

I can't believe that a nearly 11 yr old child left under the care of their Aunt, would completely and repeatedly ignore the Aunt asking them to stop doing something, if that had been me as a child, it wouldn't have been the other child hitting me, it would have been the Aunt and then my Mother when she got back and was told I needed a slap from my Aunt because I repeatedly ignored her instructions. Different times obviously.
Not blaming the girl for getting hit, but when I was that age, it was two strikes and you are out, so 'stop that' strike one, 'I am telling you to stop' strike two , followed by slap ! Plenty of time and opportunity to choose a different option.

It’s not acceptable for him to hit her however

He told her “no”several times.
He tried to remove himself from triggering situation.

She kept on pestering him despite him saying “no”
She damaged his drawing
She followed him and called him names after he decided to leave the situation.

Violence is not ok.

He has traumatic past and at 15yo he’s still a child.OP and her DP are working hard to improve his behaviour.

OP’s niece needs to learn the meaning of the word “no” and respect it. She also needs to learn to not to call people names and to leave them alone if they want to be left in peace.

Good, you shouldn't ever let her think that. But would you parent her or ignore rude behaviour? Would you let her act in a way that would be unacceptable for your son to behave?

This was completely unacceptable behaviour for which the child has apologised.

People with ‘violent tendencies’ don’t tend to ask people to stop and then leave the room when their property is taken and destroyed and then continue to walk away when they are being ridiculed. They were in a caravan, the other child was being told repeatedly to stop, presumably there wasn’t much further away he could go.