Do The Disabled Have The Right To Throw People Off Disability Seating on Public Transit?

Unless there is something about an anxiety disorder that makes it difficult for you to stand, I do not see why you needed to use the disability seating - even though you have a half-fare card. No you may not pick her up off the seat (and if you can do that, I don't think you have difficulty standing) unless you want to risk being charged with ault.