Dustbin Baby by Jacqueline Wilson

April Showers (so called because of her birth date, April 1, and her tendency to burst into tears at the drop of a hat) was unceremoniously dumped in a rubbish bin when she was only a few hours old. Her young life has passed by in a blur of ever-changing foster homes but as she enters her teens she decides it is time to find out the truth about her real family.