My mom is elderly and lives alone in a co-op. She is getting her bathroom made more handicap friendly, but has been told that there is no way to raise her wall-mounted toilet and there are no high wall mounted toilets. Her current one is about 14" off the floor, she says, and she really needs another 5 or 6 inches. Is there a type of toilet that can be installed for her that would be substantially higher or does she have to continue to use a plastic toilet riser?