FluffyPersian, my advice would be to see if you can get referred to someone BEFORE trying to conceive.
I was very fortunate to have an understanding GP who was happy to refer me to anyone I thought could help. I managed to track down a consultant who had an interest in the subject in a nearby trust (not mine own) and my GP referred me to him. Its just under an hour from where we live.
Whilst unorthodox and usual I was not the first patient he had seen who wasn't yet pregnant. He agreed in principle that I could have an ELCS.
I believe this route isn't conventional, and isn't well supported but is possible. I think the trick is to find somewhere that is experienced with handling women with similar issues. Unfortunately maternal mental health services are crap to non-existant in the majority of places. This may illustrate the problem and help Campaign to improve services and map of level of services. Care is so patchy throughout the country its scandalous. Some places you will get help and support with relative ease, in others you'll come across HCP who frankly should be held to account for their damaging behaviour.
Given your situation, I don't think you have much to loose by exploring your options now especially if you feel the counselling is not helping. You may get nowhere, but that's no worse than where you currently are.
With regard to your sister. The doctor was completely unprofessional and ignorant of what birth trauma is. Being 'textbook' is completely irrelevant and the Birth Trauma Association - THE experts in the UK on the subject - categorically state this saying 'Birth trauma is in the eye of the beholder’. In other words, no doctor can tell you, you aren't traumatised because its how you perceive what happened not their interpretation that counts. Being treated without respect or with contempt could be traumatic to some women and actually in being dismissive of your sister the doctor has done exactly that, and is in fact potentially reinforcing her fears and damaging in its own right. A woman treated well but who has a physically more invasion or damaging birth can fair better than one who has been treated badly in terms of trauma for that reason. The BTA have a good description of what birth trauma is, if your sister is interested.
She has good grounds to complain.
I don't know if your sister will ever feel able to revisit this. I do think it important that she knows that the treatment she has had is not universal throughout the UK. She's been exceptionally unlucky. There are alternatives out there who do sympathise and support her. Its a question of finding them. (which can be easier said than done). Its also important that she understands that text book births CAN be traumatic, she did not waste anyone's time (as I say she in fact does have grounds to complain as I think its not only disrespectful but the doctor was negligent). There is hope if she can find the courage.
I was treated wonderfully by some amazing people. I didn't have a problem getting the help I needed but I did do a lot of research to find where locally was best option for several years before to try and avoid hostile and obstructive HCPs. I think that if I had just gone to my local trust my experience would have been very different. It shouldn't be like this but I do feel that a little knowledge helps navigate the system better on this issue.
That said I do feel its easier than it was even a couple of years ago but there is a lot of ignorance and politics going on, which you may have to find your way through.
Good luck.