Gwent Police say Nida's disappearance is out of character and that no motive has been found to explain her going missing.
As far as we understand it she went out to the bins at the premises. That was the last time she was seen. There is no forensic evidence that she has been taken.
To go missing is particularly out of character for Nida, and officers and her family are increasingly concerned for her welfare due to the fact that she hasn't been in contact, especially over the New Year period.
We are also concerned for Nida because she hasn't taken her medication with her and is likely to become anaemic without it.
Nida is described as Asian-Pakistani in appearance, of slim build, 5ft 3ins tall with long dark hair. She was last known to be wearing blue jeans and a black top.
Anyone with information is asked to call Gwent Police on 101 quoting log number 448 28/12/13.
More top news
Dan Biggar says the Wales team are enjoying their World Cup journey and will continue to do so after the pool stages.
A cold night ahead with clear spells and mist patches forming by the early hours!
The story of how Wales have taken their qualifying campaign by storm, to put themselves within touching distance of Euro 2016.