I would wait until term starts next week, hopefully your previous supervisor will reply then. If they don't, I would send a gentle reminder towards the end of next week.

Dear all,

I have been invited to an interview for a TARA post, which involves working part-time on a PhD and supporting lecturers with teaching research methods to undergraduate students. This is my dream job! The interview is only 20 minutes long and I really would like to be offered the post.

Do any of you have ideas as to what the panel may ask me?

Thank you very much.