A personal letter from the sister of Leah Croucher is to be delivered to every household in Milton Keynes in one of the biggest ever efforts to bring Leah home.
The initiative, organised by the charity Missing People, is part of the family's poignant race against time to find Leah in time for the funeral of her 24-year-old brother Haydon.
Their dad John said: “We have days to find Leah, if she is out there somewhere,so that she can say goodbye to her brother. Please help us."
He said the need to find 20-year-old Leah was “greater than ever” after his son's death.
“Haydon was so distraught by the disappearance of his little sister that on November 16th he gave his life. We lost him as well, nine months and one day after losing Leah.
“So now instead of the phrase 'where are you Leah?' running through our minds over and over we have the thought 'two - we've lost two' playing over and over.”
The charity Missing People has supported the Croucher family since Leah disappeared on February 15.
They have organised giant billboards bearing Leah's photograph to be erected at CMK rail station and also centre:MK as part of their Home for Christmas appeal.
And Leah's big sister Jade has written a poignant letter which the charity will print and distribute all around MK over the next week.
The letter states: “During her walk to work, Leah vanished without a trace, leaving behind no clues of her whereabouts. Since then, our family have been torn apart.
"We have prayed every second of the day that our beautiful Leah is safe, and that she will be home, in our arms where she belongs.... Never in our lives did we think we would be living that nightmare. But we are.
“Christmas this year will be full of heartache, sadness and despair. It is something we are dreading. Christmas is a time for family, a time for love, and time for togetherness. For us, it will be emptiness. Leah being missing has left an enormous hole in our lives. One that cannot be filled until she is home. “
Jade also praises the work of the Missing People charity for being a “lifeline” to her family, and she urges people to donate to their Christmas appeal.
Meanwhile Leah's mum Claire Croucher has been filmed issuing a heartbreaking plea for people to help find her daughter. She is urging people to download a poster from the Missing People website and display it before Christmas.
The family continues to appeal for information about what has happened to Leah and is convinced somebody is harbouring massive secret. Other people could be protecting that person.
John Croucher said: “Our beautiful daughter left the family home to go to work nine and a half months ago and has not been seen since. Vanished. Gone. Missing. Taken. The pain, heartache and anguish we have felt as a family is unbearable. That pain grows more intense and powerful each day. The feeling of helplessness grows more powerful each day. The feeling of fear grows each day.
“We want Leah home where she belongs.”
Anybody who knows anything should call police immediately on 101 or Crimestoppers anonymously on 088 555 111.