Christine checked herself out of a medical facility in Broken Hill and was last seen on Friday April 22 near the corner of Silverton Road and Brown Street.
Attempts to locate her by emergency services on foot, in vehicles, on motorcycles and by air have failed to find her.
Police said Friday that Ms Young was likely to be barefoot and wearing few clothes.
Ms Young's mother, Cynthia Vine, who lives in the Riverina city of Wagga Wagga, told the ABC her daughter was being treated for schizophrenia.
Ms Young had gone missing from the hospital at least once before and wandered into the bush, she added.
"They said she was seen walking from the hospital, so if she was seen, she should have been taken back," Ms Vine says.
"She should have been closely watched, because they know that she's walked away from there before.
"And in that mental condition, she wouldn't know if she was doing anything right, or if she's doing things wrong."
The missing woman has a 2-year-old granddaughter and two adult children, who all live in Wagga Wagga.
Her family arrived from Wagga Wagga on Monday to help with the search.
Ms Vine said the hospital did not inform her that her daughter had walked out, and that she and her grandson were notified through social media.
Anyone with information concerning her whereabouts are urged to contact their local police station or Crimestoppers on 1800 333 000.