This is a good question and I have some knowlegde of this.
The likelyhood is that, unless you are obviously disabled looking, your GP won’t think you have it or won’t think you will benefit from having a diagnosis. However, often when you ask a UK GP for a referral, for whatever reason, people often get one, so you might be referred. The problem might then be though is where you are referred to and what diagnostic services are avilable in your local area of the UK. There aren’t many places who know about Aspergers in females and how it presents. People who do know about Asperger’s in females say that females are less aggressive, tend not to have meltdowns that boys do, have better social skills than boys, are more empathetic than boys for example. This means that females are less likely to be diagnosed with Aspergers and many diagnostitians won’t know how to spot it. Tony Attwood is a well renouned expert on Asperger’s including Asperger’s in females so you might find his material useful.
Another problem is that as you are a female adult you have to provide informants who knew you as a child and remember you well as a child. Parents can forget how you were in some ways and are unable to answer the specific questions assessors ask and are sometimes unable to give reliable answers, so a diagnosis might be made on shakey grounds. As a young female adult though your parents’ memory might not be so bad.
So, I think the chances aren’t great that an adult female will be confidently diagnosed. If you were looking to have an assessment for a female child who is having serious difficulties then the chances are higher.
Another quesion is why you would want to be diagnosed with it and how you think it would be helpful. Are you looking for support? There are hardly any services for people with Aspergers. If it is for a child or young person who is at school or college, then it would be helpful in terms of having a support worker, a study helper, computer equipment, extra time in tests etc that is if any of these things are needed. Not all people with Asperger’s need help like this though. You could get this help by being diagnosed with dyslexia though. The difference with a dyslxia diagnosis though is that it only last 2 years and you have to pay for the dyslexia test again if you need extra time for exams (which I think costs about £200 or more). If you have an Asperger diagnosis then I think accommodations for that would stand for life.
If you are an adult female with Asperger’s then be prepared that you won’t recieve any support unless you have mental health problems and need therepy from a psychiatrist or a psychologist – which you would get just the same as if you did not have Asperger’s. So, having an Asperger’s diagnosis wouldn’t make any difference to the services you get.
If you live in London there is an organsation called Prospects who offer support. I don’t know how useful they are.
I know a bit about this issue actually, so if you have any more questions then feel free to e-mail me. Below is a YouTube clip of Tony Attwood talking about females with Asperger’s that might interest you. I have lots of other clips on the subject of Asperger’s in females if you’re interested.