Non Verbal 7 year old child - how can we get her speaking? Any advice appreciated


i am getting a little desperate for my daughter who is 7, autistic and non verbal. She is a very bright little girl (knows her letter and numbers etc) but struggles to effectively communicate (pecs/ podd) and really struggles it seems to us to recall or copy words/ sounds. She has about 4 sounds for words she needs  that she uses so she does have some verbal control.

We think there may be more than the autism stopping her speaking but it seems to be accepted shes autistic and the pecs /podd keeps being pushed by her by the SALT s we see ( and i know communication is important in what ever form) but what i really want is someone to help her speak.

Any ideas on what might an alternative condition for her not being able to speak (she is such a social child)  or can anyone direct me to  people / websites that might be of help eg i am wondering if a neurologist may be better than a SALT i just dont know. I feel the quality of the life she can have will be greatly enhanced if she can speak and i just went to give her every chance in life ( like we all do as parents) but i feel time is running out for her to catch up at school etc ( she is in special school). Thanks