I'm just a parent - but having similar issues with DD1 (Y7). I think it may help if your DD were to see writing tasks - and I mean any task - reports/ critique/ creative writing/ letters - as a process. In the same way she might approach a multiplication problem or an algebra equation and knows BIDMAS.
At some point there was a discussion on secondary about a writing acronym but unfortunately I can't locate it now - maybe somebody reading this may recall it.
My advice is this:
First off teachers are marking against level descriptors/ sometimes called AFF - so understanding what they're looking for for the next level/ target level and including it in your own work will help with progress. There are lots out there - but one I quickly found was this: www.deni.gov.uk/eng_ks3_at-2.pdf - it's from Northern Ireland - but I think a lot of what is laid out here holds for England.
I also came across this writing tip advice: www.ldonline.org/article/5593/
In the US they use TEXAS as an acronym for the structure of any paragraph: T = topic/ E = Explain/ X = eXample/ A = anlaysis/ S = summary. One thing I will say is that analysis isn't just reiterating what other people think or say about an author/ issue/ topic - but your review of their arguments (well supported/ unsupported/ emotional/ logical/ etc...)and your opinion on these explanations/ views - which does not necessarily have to agree with any of them but can address something all arguments aren't addressing, or an alternative point of view etc...
Basic things to remember (just as you would with the process of a calculation in maths):
Any piece of writing needs structure - a beginning/ middle/ end - just it tends to be called introduction/ main text or argument/ conclusion. It is important to explain to the reader (because they don't fully understand your thought process) what you are going to do, then you do it, then you conclude by summarising what you've done. Kind of like the way a television documentary is organised: Tonight we're going to learn about the Moon - lots of facts and information about the moon & concludes with tonight we've learned lots about the moon and now can fully appreciate the wonderous object in our night sky which controls our tides....
With any piece of writing - if you reference your ideas/ sources of information - so websites/ newpapers/ magazines/ other books/ tv programmes etc.... and are consistent about how you do that (following school citation style, etc...) it will really help.
Vary your sentence structure - don't begin every sentence with the same word/ try to avoid using the same word over and over again.
Regardless of whether it is a critique of a book in English or a report - citing your sources of information/ doing a bit more research beyond what you were given is always a bonus - So don't just plagiarise what wikipedia says about a chemical element (as DD1 recently attempted) - set yourself a goal of looking at at least 3 independent sources of information on your chemical element (or any other topic/ fill in the blank). Paraphrase - write in your own words - don't just copy.
Research - in English criticism ask yourself whether this story is similar to other stories (by the same author or others)/ is the author adapting a well known story? i.e. is Pride & Prejudice really an update of Taming of the Shrew?/ find out more about the author (s/he's writing from the heart/ experience/ political viewpoint/ etc...). All much easier with the internet.
Going that little way beyond writing about George Orwell's Animal Farm and just talking about your interaction with the book - but finding out who George Orwell was/ what (may have) inspired him to write the book/ how it was received when initially published/ how it is considered today - will all help to make your work stand out. Was this his first book? Was this his final book? Did it relate to his working life? What 'genre' would this book fall into - not just fiction - but would it be political commentary? Dystopic future vision? Fantasy? etc.... Has the story gone on to inspire other writers/ cinema/ etc....
With research papers - so let's take the element project - don't just rattle off a list of information (as DD1 did initially with how her element was used without understanding exactly what that meant). If you're
discussing something and don't know much about it or understand what it means/ how it's used - find out more. (again easy with the internet).
PLAN - before your write really think about what it is you're trying to do - answer a question/ explain why you like a book and what particularly you like about it/ research into a topic a bit further/ report information to someone who knows nothing about the topic/ etc.... Take the time to think up ideas/ outline your paper (basic structure)
Finally - and many people forget this - presentation is half the battle - put the time in to write out your work neatly (if hand-written), or lay out your work (with images/ drawings/ diagrams/ graphs etc...) clearly and in an eye-pleasing way. A good presentation can make up for a lot of weaknesses in your text. Certainily DD1 keeps making the mistake of writing reports/ essays immediately into her class workbooks - instead of working up a draft.
I can see that ASD can make this transition to a more mature writing style difficult - there may be resistance to learning these new approaches initially - but from this point forward (right up to University) these are the basic skills you need to succeed. My DH deals with this kind of issue a lot at University (in his Welfare/ Tutor roles) - and he advises that if these don't work you should speak to the SENCo - because this is holding back your DD and it does sound like she could use a bit more support with this.
HTH
HTH