Advice required

Absolutely! This lass deserves better than she's getting.

One thing jumps out at me from your post:  ‘the school have said that she is ok with the academic side there’s no point filling in the forms for the school nurse team to just knock it back’. 

THIS IS RUBBISH ADVICE.

Some Schools have a tendency to not properly address the needs of pupils who are quiet and well behaved - especially if the academic side is ok. This is - frankly - laziness and not acceptable. Lots of autistic children do well academically - that doesn’t mean they are necessity ‘ok’. 

Don’t accept this from the school. Your daughters behaviour when she comes home is most likely a release from all the pressure she is feeling from masking and trying to cope in school. It’s basically an outlet for her distress at school. 

Try to talk to her about school to find out how she feels about it. 

Schools often tell parents that ‘there’s no point trying to get a diagnosis’ or ‘an EHCP won’t make any difference’ - this is rubbish and you don’t have to accept it. 
Do your research, get informed, and advocate strongly for your child’s needs. Don’t just accept what schools etc tell you - often there are a lot of other reasons behind their wish not to get your child the help they need. Some schools lack the appropriate commitment to children with SEN. It’s a shame but you have to be on guard for schools that are quite happy to fail our children. 

To me this also sounds like she has to make a huge effort to mask and hold it together at school, so when she comes home it just all comes out. It reminds me of myself : I did very well academically and was very well behaved at school but at home I would often get into bad arguments with my stepfather, I am ashamed of this but I think in a way this was my way of letting off steam. School can be extremely draining and exhausting for an autistic person. Just because everything seems fine on the academic side doesn't mean it is all fine- it can take a huge huge effort. I'm sorry, I don't really have any practical advice- I just wanted to say I can relate to this- to being a different person at school than at home or in other settings and  it can be very exhausting. I don't know but I think the masking and not being able to be yourself and take care of your needs can be a huge problem- I wish I had known that I was autistic at the time- it's a fine balance, but I wish I had masked less and had been more accepting of myself and my needs- it can be so detrimental - Have you talked to your daughter about school and what she aspects she finds difficult and what she thinks could help? 

Does your daughter have a diagnosis yet? If not, the school or your GP must take this seriously. If so, the school need to be doing a lot more to help reduce the sensory and social overload.  She may look fine, but she is far from it, poor love. She will have been 'controlling' emotions and sensations she maybe can't even pinpoint ALL day to an unimaginable degree and by time she gets home, just can't do it any more. Her system is way overloaded and needs to exorcise it.

The explosive meltdowns at home are the result of her daily distress. It's huge and she can't help them. All I can suggest there is that for the sake of the rest of the family, she has a space to go and be safe while they play out. Maybe if she develops an understanding of why she's going through this, knows she's not to blame for them, but knows she needs to play them out other than on people (depends on how well she can feel it rise, or whether they take her by surprise)...

Can you get her a punch bag she can release her furry on? I have a cousin, also on the Spectrum, who is at university now. Lovely, kind lass, but this happens to her too. She uses the punch bag to vent the overload.

We had similar problems when my son was in Primary. We kept a diary of the effect the masking in school had on my son. This may be helpful in showing how this affects her.

It sounds like she's not 'settling fine' at school. She's basically holding her breath for a whole school day. Every day.

here's a good example of what Fight/Flight can look like in autistic children: https://twitter.com/TheSENmumTA/status/1524290105107701761/photo/1

We have difficulty with language, syntax with sorting out internal emotions and communicating what's going on. So it's necessary for parents to ask if their child has exhibited this kind of trauma response and when. Don't be fooled though, humans are capable of shutting down when captured and enslaved. But I'm always amazed at how it's OK to torture autistics simply because most aren't designed to be impacted the way we are. 

If she's OK with the academic side, then perhaps as someone she wants to trust to protect her, you could try homeschooling if that's an option. I can understand it's not for everyone. Should you be able to, you can assess if she's actually stunted by school academically and would be far excelling where she's at if she wasn't overwhelmed by the sensory environment, by the social chaos. 

30 years ago when I was in school, I was allowed to sit in a quiet study space during lunch. I was allowed to go to the library instead of recess. Adult Humans were sensible beings. After all, the area where the teachers take lunch is quiet and sometimes carpeted. The noise isn't bouncing around and piercing or overwhelming. We're not a homogenised herd. Some don't thrive shoved into continual non-stop daily chaos.  

This woman can help give an understanding of what autistics deal with daily https://www.instagram.com/thearticulateautistic/

We won't ever dull our senses like most. It's been noted that our oscillations of brain waves can be different in the Beta band leaving us open and vulnerable for life. This can help us become a specialist and a valuable resource to society. But as children we need parents who can recognise when we're in pain and protect us from the elements, believe us when we express the world is too much, and help us renegotiate sensible and more humane ways of being with in the world.