A quick-thinking four-year-old girl who called 999 after her mum suffered serious injuries when a bookcase collapsed on top of her has been commended by police. Brave schoolgirl Lexi Cooper potentially saved mum Nicola Ellis' life when she rang the emergency services following the accident on December 5 last year. Lexi, who was at home with siblings two-year-old Harry and one-year-old Amelia, managed to tell Contact Centre Agent Sophie Roscoe vital information and desperately tried to rouse her mum until help arrived.