The first line of treatment for young children with ADHD is behavioural therapy. If that fails, medication may be considered.
I think this is a pretty appropriate approach and would advise against trying to skip the first step.
+1 to this.
I'm also just a wee bit concerned about the idea of OP asking about drugs for a 6 year old that is not his. It sounds like she's at least worked with a doctor enough to obtain a diagnosis and decide against a course of treatment. It may be best to just let her do her thing with her kid under the care of a doctor.