No marking or comments whatsoevet in exercise books, year 7

I wouldn't necessarily mark actual books on a regular basis. I set homework that is project-based and collect those pieces in separately from the books. Most of the book work is done in class and is either copying notes/diagrams from the board or doing questions that I will then get them to peer mark themselves. However I assume if she's brought the book home than she has been set homework which I would expect to be marked.

How do you know it was marked that regularly in primary? As a primary parent you would surely only see their books at parents' evening so would not know when the work had been marked!

Is this in every subject? Ds in yr 7 has one subject with no marking yet (and a core one) but they've had lots of testing and other events which mean they've missed this subject more than others and also teacher has set a long homework so let them keep their books rather than taking them in. But for all other subjects, all marked weekly and levels/marks as per the guidance sheet stuck in back of books.

I try to mark all work weekly but this is not always possible due to the constraints mentioned above.
Exam classes will always get priority so it will sometimes be fortnightly for ks3 pupils but never more than 3 weeks even coming up to exams.
If I can manage this with 2/3 timetable of exam classes and Head of Dept duties in a subject which requires a lot of writing (History), it seems as if your school is being somewhat underwhelming.

Exercise books should be marked regularly, with appropriate comments and levels (although not all appropriate). At a minimum, there should be some acknowledgment that the book has been looked at/checked.

This may not take place as regularly as you are used to in primary schools. Some schools have rigid homework timetables, and teachers may only have one opportunity per fortnight to take in books (I certainly have this situation). An unfortunate teacher may be 'scheduled' to take in 3 sets of books in one evening, only to have them all back, marked, within 2 days. With loads of other time constraints this may not always be feasible, so books may not always be marked when scheduled.

That being said, I would expect most subjects to have taken in and marked books by now. If this is routinely not being done in the school, there are serious concerns. Ofsted are very hot on marking.

Does the form tutor check the homework diary? If so, maybe put a note in about the subjects of concern.