If you check the website of her Montreal centre, you will read
For example, the Lidcombe Programme for Early Intervention in Stuttering has been credited with eliminating the progression of stuttering in preschool aged children within a mean 11 clinical hours, with fluency being maintained for periods up to 4 years.and further
Studies have shown that stuttering can be maintained at near zero following treatment.These statements are misleading. If she were not a pseudo-researcher with fuzzy thinking, I would even accuse her of deliberately lying to parents of children who stutter.
Check my post on the follow-up study of Lidcombe: here and here. Even this flawed study shows the relapse. In which dream world do they live?
Again, Lidcombe might at best modulate stuttering and psychosocial adaptation to stuttering, but not more. But other treatments might well do the same.