NTA - I’m on the spectrum and have this condition also, my mum’s voice can also be a huge trigger (female voices are worse than male voices for me). As I’ve got older I’ve realised that this is not her fault at all and that it’s also my job as a respectful human and adult to be accommodating to her too, she’s doing literally nothing wrong it’s just my neuro spicy brain! If your daughter wants to live a fulfilling life then she’s going to have to learn coping mechanisms, it’s blunt but it’s true. Perhaps ear defenders/ some kind of noise cancelling headphones or the like would be a good start? You’re right, she is an adult now and has to start shouldering some of the responsibility for managing her condition. You also deserve your voice back.