@ Sh and Sh... I am glad that you were able to contact an immigration lawyer...
I would suggest contacting ( or just shoeing up ) at the medical office, to explain that this is a 'update- re- do'... For a ' non- accompanying child'... I am hoping that they will give you a chance to re- do it
Re: Writing KNG a letter in regards to 'mother's lack of cooperation to do child's passport '... I think this a good thing, but I would suggest that the process for getting the PP is started anyway, because it will be needed sooner or later, and will be easier for your hubby to oversee while he is still in JA
Re: whether or not it is necessary to have ' non- accompanying' child update medical ... In my situation I had sent them e- mails to verify if it is needed ( because child was not coming now).... They never responded, I updated it anyway, because I heard it can delay your application ( incomplete)...