PIP Activity 7 - Talking, Listening and Understanding - Do any of the descripto

Hi there
I am currently completing the PIP form for my 16 year old who is transitioning from DLA to pip. When completing the form it helps me (also autistic) to have an understanding of what descriptor should apply, so that when we get our decision we know whether it needs challenging or not. For the majority of activities I can see clearly what descriptor should apply, But I am stuck on activity 7 (Talking, listening and understanding). My daughter is high functioning autistic and also chronically ill with several debilitating conditions that impact her fucnctioning on the majority of days. We have over 20 evidence letters supporting everything we have written in the form. But activity 7 has thrown me because her communication ability fluctuates. On the majority of days she can communicate very eloquently IF communicating with people that she knows, is comfortable with, and she is feeling well in herself. However when feeling overwhelmed, either emotionally, sensory, or by her physical symptoms, which occurs for periods on over 50% of days, she either shuts off, only being able to communicate on a basic level of one word answers/brief interactions, or she switches off entirely and doesn't talk at all. This is with both familiar (including immediate family such as me) and unfamiliar people. When she is like this at home, we pick it up and give her her space. When like it outside the house, she needs me to be her voice (such as when interacting with medical professionals and members of the public). Her EP report sets her communication difficulties out clearly, and states in her educational setting she needs communication cards (which detail that she can go non-verbal and not to try to get her to talk) and staff working closely with her need to be trusted, attuned and trauma informed. I have no idea what descriptor would apply, if any, given the fact that she can also talk very eloquently on the majority of days, and her periods of struggling to talk are unpredictable as her triggers can vary.