6 year old daughter with adhd and she is non verbal. started retaline about a month ago. she came back from school with bad mouth sores. she seems a bit tired and her eyes are red. she refuses to it. what could be the problem?

Usually viral: Such mouth sores are usually a transient viral infection. A drug reaction would not take a month to emerge.Feed her ice chips & chilled foods/liquids to dull the pain. See her doc if she isn't taking enough fluid to pee every 8 hrs.

Doubt related: I doubt her mouth sores and red eyes have anything to do with the new medication. Most likely caught some viral illness at school. If she has been having fevers with her other symptoms, would have her evaluated by pediatrician to make sure she doesn't have Kawasaki disease. Push fluids and soft foods like yogurt that won't hurt her mouth. If refusing to eat or drink, needs evaluation by doctor.