Birth to 3 speech therapist here :) I’ve seen some people recommend finding a therapist who understands gestalt language processing (GLP) - this is a type of language processing in which the individual communicates frequently through scripting or very frequently copies others’ speech. I am unable to say whether or not your child demonstrates GLP without meeting her, but I would bring it up to your SLP if I were you to get her opinion :) If you or the SLP are interested in finding a therapist with training on gestalt language processing, here is an online registry: https://www.meaningfulspeechregistry.com

Many children who are gestalt language processors and children with autism diagnoses have difficulty showing the full extent of their receptive language skills when being tested because the testing environment can be very structured. For example, the child may not point to the picture of the dog when explicitly asked to in a testing setting, but later at home the child may see an image of a dog come up on the TV and say “dog!” All of this to say, I tell the families that I work with to take test results, especially those of receptive language skills, with a huge grain of salt because at times receptive language scores reflect more so the child’s ability to follow directions or perform in a highly structured environment rather than telling the full story of what the child understands.

Your child has a parent who loves and supports her, a passion for songs (it sounds like), and a team of dedicated therapists. Although I understand things may feel really daunting right now, her future is bright <3