Humiliating punishments for a tall girl

So i have a sub shes 6'4 and recently shes been very naughty just breaking rules constantly not looking very sorry and the punishments ive always used mainly spankings arent seeming to work anymore shes very shy and reserved so i think a new humiliating punishment maybe even in public would work wonders but ive never done anything like this and i dont have much in mind i thought id see if anyone here had some good ideas

As a tall girl I would have take her to the bathroom, strip her completely, and make her hold onto the shower curtain rod (or faucet if no rod) ; then take your time with a spanking/maybe hairbrush or ruler, and when good and rosy give her full bag enema and have her hold it as long as you desire- having to keep her hands on the rod or faucet exposes her nicely and makes the enema much more uncomfortable with no easy way to gain relief and is also embarrassing- you can also pinch nipples or do other interesting things if you need more tricks