Seems like there may be a motivation issue. What thinks does your daughter enjoy? Finding ways to make learning enjoyable for kids with ADHD is important because it an be harder to focus on things you don't like. Her medication may need adjusting as it sometimes can as kids approach adolescence. But there could also be social things going on. I would back off of academics slightly to find out what really motivates your child and then use that to connect with the importance of education.