how about restrain her so all she can do is lay there like a real infant. only bottle feed her and make her stay still for a day, she'll be hungry but not starving and a day is a long time to not move.
another idea is to make her wear baby mittens for a while so she can't use her hands.
umm, Idk tbi is a generic term, I believe that the mind is in the brain, therefore its possible that any action or belief can be caused by a brain injury