As has already been said make sure you know the reasons why you want to be a teacher. Also, have examples of how you have worked with children that has been benefical to them- e.g. helped a child achieve something, overcome a difficulty.
It may be worth your while reading TES on-line, or buying a copy of TES. At my interview I was asked about hot topics in teaching (at the time it was the idea that they have fewer teachers and students were taught by video link). It shows you are current with educational thought.
why you want to do it?
what makes you think you can do it?
how you will prepare for the course- any work experience, guiding etc
why should they pick you?
what have you already wrote on ur statement as prepare another so ur not repeatin uself but actually sellin urself an addin in more of ur qualities
Primary is so competitive, make sure u have ideas of engagin students, any good lessons you've seen