The system of secondary education is functionally broken for the 5-8% or so of the population with ASD and ADHD who should be able to access the mainstream curriculum.
Schools are so big that 5 times a day there is a massive mental onslaught of getting through noisy, aggressive corridors which are a hostile environment.
And most town secondaries are now so large that just getting 1500+ pupils fed is such an unachievable logistics issue, that the option of eating lunch is either 11.20 in the morning or after 1.30. Which normal human functions & learns well with timings like that?!?
Most adults would struggle to function normally in these conditions! The 90% of pupils who tolerate & occasionally thrive in these conditions would still do better in smaller, less hectic settings.
There are some schools which have managed to obtain the educated, nurturing and informed SEN staff, and the appropriate physical spaces to support those whose diagnosed medical conditions mean they're just going to go wobbly if they have to constantly operate in this hostile, big, loud, abrasive, school environment.
Accommodations like moving classroom 5 minutes early, hall passes to get to a quiet support room & education for the entire teaching staff so non-compliance is dealt with by self-removal rather than blowing up into a massive confrontation in front of an entire class are managed exceptionally well by some schools - and treated as an impossible anathema by others.
In these large schools with 1500+ pupils, there are going to be 100 or more children who would benefit from these kind of options-even if they don't ALL need quite that high a level of SEN support all the time.
When you look at the entire ecosystem that exists around fighting them at every level from getting assessments & then battling resistant schools (the ed psychs, OTs, CAMHS, social workers etc etc described here). SURELY it would be better value to our entire society & the future careers & earning capability of these pupils just to get the support right from the outset?
Or maybe what we can do in 5 years time is commandeer all the small private schools which will have been put out of business but seem to manage to offer a full curriculum to 100 pupils or less in a year group now - and educate those who need less upheaval in their school day there instead? It will surely cost less than it does for all the specialists, civil servants, social workers & lawyers do at the moment just to try to PREVENT these children from accessing an appropriate education?
Good luck OP. Your daughter deserves to get support for what the ed psych has suggested. It's really not rocket science!