In reply to PaulW:
Great! Yes, the instructor said to try ladies x small for the harness.
Also, can I just ask which forum you think would be best to ask about this: I know he would love to try actual outdoor climbing. He's apparantly a v good climber, but the issue is that he has autism and needs a 1:1 instructor at the moment. I don't know how to find out if there are any options.
Thanks