As with all situations like this, there will always be significant details which haven't been printed. It seems unusual that the council (social care) would have taken out the order when it is the CCG (health) who would have been paying for the bed at St Andrews.
I imagine the council don't want to end up providing a placement when her health needs are clearly as high as they are. Even a basic placement to cater to such needs can be £2,500 a week, which is a lot for a social care budget.
The cost of the bed at St Andrews is not that extreme given the provision. As others have said you need to factor in 24/7 nursing, psychiatrist, health care assistants, medication, occupational therapist, social workers, security staff, maintenance, it all adds up. For example I used to work in a non secure residential placement for severely autistic children which was £250k a year with no health provision.
There are mechanisms to review detention in secure hospitals. Either via a mental health Tribunal (if she is detained under the mental health act) or a care and treatment review by NHS England. I imagine these will have happened but aren't mentioned so I'm sure there are loads of things missing.
Edit: reread more closely and it does say she could only be discharged by a tribunal. This suggests she is detained under section which means she would have a 6 month or yearly independent review by a panel. They can't make a statutory decision as to whether she stays in seclusion or not, but they can make non binding recommendation. They can also decide whether to discharge her or not so the fact they haven't suggests she's in the right place, as unfortunate as it sounds.
