1. Yeah it is fairly common. People have different kinds of secondary behavior they do when they stutter. I personally, invoultarily make facial contortions and slight head jerks. People develop these secondary behaviors to help them get past speech blocks but it very quickly becomes just another bad habit they have to deal with. 2. Listen to her patiently. DO NOT finish her sentences. Let her speak as much as she wants. Trust her completely. Be someone to her with whom she can share everything. Patience is key! Also speech therapy is a wonderful idea.