I was diagnosed via the NHS at a specialist clinic (associated with the autism research centre) 2 years ago, my daughter was diagnosed privately via an autism charity (because the children's mental health service is an absolute disgrace, every person I have come across has had a negative experience with them) a year ago. From when I first went to the GP to actually going for my assessment was just a matter of months (4 I think) but that was in part due to the clinic having a cancellation and a really good GP who helped get me referred (after a member of the mental health team tried to say I just had OCD when she skimmed through my notes and didn't listen to what I was saying).
I had to fill out an application form and do the AQ and EQ tests and my mother had to fill out a CAST test before they would give me an appointment. I did worry that they hadn't received the documents so I phoned and was told I would definitely get an appointment (I'd scored very highly on the AQ/CAST and low on the EQ so passed the screening). The person who conducted the assessment first interviewed my mother about my childhood and then I spent about 4 hours in the interview, at the end she was convinced I had Asperger's but had to take my results etc in front of a panel before giving a firm diagnosis but she felt it would be a definite yes.
My daughter's diagnosis was difficult, I already thought she was an aspie too(because she has many traits) but my husband was very against it, a hospital nurse suggested we seek psychiatric help after our daughter had a procedure, in her 15 years working with children she'd never seen a child react so badly (screaming, crying, refusal, etc). We went to her GP who referred her to the children's mental health team, we saw a registrar, explained to her the hospital problem and I explained that I thought she was on the spectrum too and explained her various traits. She was referred to an Occupational therapist for her sensory issues and a play therapist for the hospital problem. 2 sessions in, the play therapist said she couldn't help her, the problem was far too complex for "normal" therapy but she wanted to keep seeing her (we found out much later that she was making notes on her for the registrar). The occupational therapist confirmed she has significant sensory issues and made suggestions to help her in and out of school and arranged to go in and observe her in school to give more specific recommendations for school.
As the asperger route didn't seem to be getting looked in to I asked her GP to refer her to a local autism clinic for assessment, that letter was redirected from that clinic to the mental health team and her play therapist called me in and asked why I had done it and I explained because nothing was being looked into, she said it was that they had her down as borderline asperger's but just needed the school's report on her before proceeding.
We were called in to see the play therapist and the registrar who basically said no not on the spectrum I asked how they came to that conclusion and was told she'd played in a socially accepted way(I pointed out that was with an adult not her peers and was not the be all and end all of autism). I brought up her sensory issues (which they could not deny as OT had confirmed them) and they shrugged it off and said she may have a sensory processing disorder but was not on the spectrum. They whipped out the school report that reported a happy, pleasant compliant girl with some receptive language problems...but apparently that was proof she was not an aspie because she was not acting out at school. I brought up every trait (obsessions, literal thinking etc) and every single issue they said was basically down to her being a spoilt only child.
So we left before I ended up smacking someone and I sent a very nasty complaint letter, demanding a proper assessment, including all sorts of information regarding how an assessment is supposed to be done, how autism is different in girls and by that time we had been to the charity and had a pre-assessment and their opinion was that she was very likely an aspie. The mental health manager overturned the decision and we were told she would have an assessment, what we actually got was a rigged, quick ADOS to cover the teams butts. The ADOS assessment was done by a paediatric cardiologist (yes you read that right a kids heart specialist) NOT an autism specialist, she led my daughter into saying the right answers, so when she had to look at a book and explain what was happening my daughter just shrugged, the woman put words into her mouth by saying "well do you think maybe the frogs are doing this..", my daughter would nod and this woman wrote down that she was able to explain what was happening in the story! When she was asked to make up a story using some random objects my daughter played out a scene form a film word for word, when I told the woman that, I was told it was irrelevant. She was scored 0 on things such as obsessions and rituals (despite me telling her all of her rituals that have to be done or she won't for example sleep, explaining about her monster high obsession). This woman also tried to pick apart my diagnosis but she had to shut up when I told her it was done at a world renowned clinic by an autism expert, she then tried to blame my daughter's behaviour on ME being an aspie, that me being on the spectrum somehow messed her up. She then said she was not on the spectrum but may have PDA (which is considered part of the spectrum so showed how uninformed she was), which was based on her saying stop standing on the chair and Kyoko didn't, I told her to get down and she did...but yeah because she didn't do it when the cardiologist asked that concluded she had pathological demand avoidance...total idiot!
It was an absolute disgrace! We went back to the charity who did an ADI-R assessment (as well as observing her) that lasted about 4 hours, she scored 3 times the cut off points and was diagnosed that day. A few months later her occupational therapist (wonderful woman) realised her recommendations were not being implemented in school so to back her up and get Kyoko extra help she referred her to speech and language therapy who assessed her and again confirmed she had language issues consistent with a child on the spectrum.
I made a further complaint to the children's mental health with all this information to back me up, an investigation was done and the outcome was basically a shrug and a goodbye. Our story is basically universal with aspie girls (not sure about boys), the facebook group I'm a member of (we all have girls with/suspected asperger's) every one of them has had almost identical treatment, being told no not on the spectrum you're just a bad parent/she doesn't act out at school/ she made eye contact/ she can play/ other ridiculous reason for not diagnosing.