Millie Inbetween Series 3 ( Air Date 2016-11-23 ) Genre Comedy, Family, Kids category. Overview "Millie’s parents have just broken up and she and her sister Lauren are spending time at both Mum’s house and Dad’s flat. Millie soon sees the advantage to this family set-up as she has two chances to celebrate Christmas, two birthdays and two bedrooms. Problems arise however after her parents find new partners.".