Daughter of nearly 4 just been dianosed Autistic

I have had people ask me what acronyms are on other sites and likewise I have asked what acronyms mean myself.  No-one appears to have been belittled by having done so Longman.  I suspect you are reading way too much into this, and like you say, the term "NT" is used more than enough here and elsewhere.  You also have to remember context, alongside the term GP (don't tell me I have to explain that one too!) it becomes patently obvious (and yes, it is health visitor).  OP has not stated that she doesn't understand.  People seem to communicate in text speak these days anyway.  I kind of therefore feel your post was unnecessary.

acronyms are very difficult for the unfamiliar - and health ones are notorious. I assume you mean Health Visitor. Sorry, not trying to be pedantic but people seeking help on this site may not feel good if jargon is used they feel belittles them if they have to ask what's an HV.

OK we're all guilty. I know NT winds up the non-autistic visitors even more than calling them neurotypicals 

You could speak to your GP, or HV if you have one, to ask about services such as child development centre.  Perhaps contact social services for an assessment of need.