A fantastic portrait of an ambulance driver or attendant - the name on the rear is Elma May Stamp (nickname Buzz). The lady also wears a medal ribbon which looks to be the Royal Red Cross (which is a blue centre with red bars either side). The award is made to a fully trained nurse of an officially recognised nursing service, military or civilian, who has shown exceptional devotion and competence in the performance of nursing duties, over a continuous and long period, or who has performed an exceptional act of bravery and devotion at her or his post of duty. There looks to be an additional badge on the shoulders of her coat but it is not possible to discern what this relates to.
News about interesting insignia, ARP related info and period photos that turn up.