Hey there meandb!
My little girl isnt 9 yet but we struggle with emotional regulation also. One book I have found that has been helpful (sorry if someone already mentioned it, as I didn’t read all the responses) is called Smart but Scattered… and I can’t think of the author, but it talks about executive functions – which is exactly what is hindered in the child who is on the adhd spectrum. It helped me to identify my child’s mental/emotional/intellectual strengths and weaknesses. It also gave practical advice on how to work with your child to strength their weaknesses.
On a personal note, you said your daughter sees everything in black/white- I’m not sure if you’re familiar with CBT (Cognitive Behavioral Therapy), but a great deal of those undesireable hang ups can be combated with ‘talk therapy’. I wish I had the website that helped me understand this further so I could post the link for you, but I don’t. You’ll have to look it up. If you can’t get her to see a counselor, you might be able to learn some skills to help her work through her feelings by challenging her thoughts/attitudes, which will impact her behaviors and also her feelings.
Sorry if I’ve left you confused.