Rachael Lawrie went to school as usual on Thursday morning, and was later spotted on Newbattle Road around 11.50 am, heading towards Easthouses.
She has been described as around 5 ft 5 ins tall with long, fair hair.
It is not know what she is wearing.
Sergeant Ross Falconer said: “Rachael has been reported missing before and we are concerned for her well-being and would ask anyone who has seen her or knows where she might be to get in touch.
"If you can help please call us on 101, quoting reference number 1296 of Thursday, 26 May, or get in touch with any police officer.”