The PSNI said four masked and armed men entered a house around 9.30pm and ordered the woman who was in the house to go to her place of work in the Boucher Road area.
She was told to remove cash while her partner was taken away in a van.
Two other adults and two children who were in the house at the time were unharmed.
The woman followed the gang to the commercial premises where she works, removed money from the safe and handed it over.
Once this was done, her partner was released from the van unharmed.
Detectives investigating the incident said they would like to speak to anyone who may have witnessed a light-coloured van acting suspiciously in the Stewart Street area of the Markets or a Renault Scenic acting suspiciously in the Markets area.
Anyone with information should contact the PSNI.
