Child with undiagnosed severe learning disability

Hello all.

I'm new here.

I have a 10-year-old daughter who's autistic and has a severe learning disability.

I'm struggling to get a learning disability diagnosis for her when her disability is 100% obvious.

I'm looking for advise about getting a diagnosis for my daughter, please.

My daughter was diagnosed with autism when she was approximately 4-years-old. At that stage the paediatrician stated that my daughter also seemed to have developmental delay. Now that she is 10-years-old, it is very obvious that she has a severe learning disability. However, I am now struggling to get my daughter's learning disability diagnosed and I simply can't understand what to do. My daughter's learning disability is not ambiguous, she is completely dependant on adults to help her with everyday activities including socialising, she is non-verbal, she will never learn to read or write, the list goes on. There's no ambiguity in her disability. My daughter isn't just autistic, she's autistic with a learning disability.

I've approached my GP who then contacted me to say that I should approach the school instead for a diagnosis, and then the special needs school my child attends, stated that this isn't something they do. I don't know what to do and feel as if they are both lying to me so that no one has to do anything.

A learning disability diagnosis will mean that my child gets the right support for her needs as well as deal with matters of mental capacity and consent. I don't know who else to turn to and don't know what to do next.

Has anyone had their child diagnosed later on in life rather than at birth or toddler years?

Any advise or suggestions is most welcome and sincerely appreciated.