She is known to have links to both Lanark and Glasgow.
Rachael is described as being 5ft 5in tall, of medium build with long dark hair.
Tom Jones Edinburgh: Princes Street Gardens concert stage times, support, setlist and how to get there
West Lothian crime: 'Horrendous' child rapist labelled 'utterly appalling' by judge
Edinburgh Airport: Taxi firms set to bid for control of rank as tender released
West Lothian crime news: A survivor of abuser Malcolm Andrew McDougal has spoken out about her experiences as he is found guilty in court
Irvine Welsh: Trainspotting author marries former Taggart star Emma Currie
She was last seen wearing a white hooded top, black leggings, white Converse shoes and a black backpack, but may have changed clothes.
Anyone who believes they may have seen or spoken to Rachael at any time since Monday is asked to call 101, quoting incident 1389 of Monday, June 27.
Meanwhile, local Community Officers will be holding a police drop-in surgery at Roslin Library between 10.30am and 11.30am on Monday, July 25.
Pop in and speak to police regarding any issues, concerns or for some crime prevention advice.