We are becoming increasingly concerned for her welfare and urgently need to make sure she is ok.
Lydia - who has been missing before - is white, 5ft 8ins tall, of slim build and has long brown hair. The 14-year-old is believed to be wearing blue jeans, a white t-shirt, black leather jacket and black trainer boots with a glitter design.
Anyone with information on her whereabouts is asked to call 999 or the Locate team on 101.