Lying in kids with ADHD has to be viewed as a symptom, not as a character flaw. There are a lot of reasons kids lie — self-preservation, fear of repercussions, not wanting to disappoint parents, to express how something felt to them, etc. When you pinpoint why she is lying in different situations, then you can address it and reduce the need/compulsion/impulse to lie.
Penny
ADDitude Community Moderator, Parenting ADHD Trainer & Author, Mom to teen w/ ADHD, LDs, and autism