Daisy Burton left her home in Brigg told her family she was going to Grimsby but has not been in touch with them since.
A police spokesman today said: "Daish has links to the Peterborough area and it is thought she may have tried to travel there.
"She has a number of health issues and we're now growing concerned for her welfare."
Daisy is described as being 5ft 4in and slim, with long, dark hair.
She was wearing black clothing including jogging bottoms, a hooded top and a Superdry coat.
Anyone who has seen her or who has information on her whereabouts is urged to call 101, quoting log 189 of April 25.