In reply to jo99:
Hi there,
I used a full body harness and climbed until I was about 8 months at which point it became increasingly uncomfortable to do...well anything! The harness did the job. It felt strange to climb in, but toproping was manageable. In the end I was limited by my size. My centre of gravity shifted, and many moves became well nigh impossible. At that point it wasn't enjoyable anymore so I sacked it off. Good luck with it all!