Have finally managed to get into the blog... sounds like some pretty heavy stuff there.

Document everything. Every target set, every goalpost moved, every comment about 'do this or you're fired', every minute spent at the office over her allotted hours - there's a serious breach of Health and Safety right there if she's alone in the building, insurance cover might not extend to unpaid, unapproved overtime - keep a diary of incidents WHERE THE BULLY CANNOT GET AT IT... Don't trust a work locker or locked desk drawer.

Try to check the work records for when this bully goes away for a week - was the work completed? Is the office a happier place to be? Does the bully even take a week off? Many bullies feel that the office will fall apart without them, so they take the bare minimum holidays they can get away with, usually less than 3 days at a time. They set impossible tasks so that only 'they' can save the day by "good management" - for which read threats and harrassment. When they see you attaining the target, they will move the goalposts, to imply that you cannot work without their guidance.

Good luck.

LTS