First, I’m really sorry that you are struggling with this. It’s really difficult to navigate. I have 2 children with ADD, my son was diagnosed at 7. It was obvious from very early on. My daughter was diagnosed at 13 and we missed all the signs because they are so different in girls. So many years I made the same mistakes, begging her to tell me why she lied about EVERYTHING which just made her tell more lies to avoid things that she was having trouble processing. She’s lied to me, my husband, her teachers, her friends….
Your daughter is not a bad kid. She is actually pretty awesome with her ‘different brain’. She just can’t process in the moment and she knows you want an answer and she gives you one and usually it’s all downhill after that. It’s a process to work through and help them to be more mindful of this. Making it a negative just invites more shame and that’s a hard cycle to break.
Learn as much as you can about your daughters brain and help her to understand what she is able to at her age. Parenting with love and empathy is so important. I spent so many years not understanding why my daughter was the way that she was and I felt/feel immense guilt that we missed it for so long and we’re having to help her relearn healthy coping skills. My pediatrician said now that I know better, do better. I spend my days learning about my kids brains and devour books and podcasts. I have made it my mission to advocate for my kids and love them for the people that they are and not the people I had hoped they would be. Our life is a circus, but it’s my circus.
So many resources are geared toward boys, this was helpful to both me and my daughter. https://www.amazon.com/Attention-Girls-Guide-Learn-about/dp/1433804484/ref=sr_1_3?keywords=girls+with+ADHD&qid=1560175859&s=gateway&sr=8-3
All the best!