I might be wrong here and await incoming if I am.As the following is the official description of the ACF , I find it highly unlikely that someone who is not part of the Army could be 'army qualified'. Perhaps you need to remind the youngster that they are in a nicely titled Youth Club but are merely sponsored by the Army not part of it.
'The Army Cadet Force is not part of the Army. However it does use the uniforms, traditions and badges of rank of its Regular and Territorial Army sponsors. All adults in the ACF are youth workers..'