Gemma hun, I think for you exercise would be the best thing as it would tone up what you have got. After weight loss skin can take a long time to shrink back, although the younger you are the quicker it normally is. However if it is wobbly, building the muscle in your arms would help to stop that, and although will not shrink what you have, it will make it look much better! Trust me, I still have a way to go to get to goal but am already working on my arms in the gym and can see the difference, despite the fat thats sitting on top of my muscles!!
xxx