Collaboration is an important feature of today's teacher education. According to several researchers, teachers are open to work collaboratively, although they often work in an individual and solitary manner. Since the nineties statistics education includes the need for children to be able to pose questions, collect, organize and represent data in a spirit of investigation and exploration. This is enhanced by implementing student projects. The main research question in this paper is to clarify how three pre-service math teachers planned and prepared classes and reflected afterwards upon them. A qualitative methodology was adopted. It is shown with empirical evidence that collaborative work between teachers is an important approach to solve difficulties in statistical and didactical knowledge. Our results also show that these are the areas teachers have to improve in order to become more confident teachers of Statistics.