The incident came to light when a case of theft was reported at a jewellery showroom last night, sector 20 SHO Rita Yadav said.
On the pretext on seeing the jewellery, the accused took a large diamond-studded bangle and stole it by dodging the salesman.
When the jeweller tallied the items at night, one bangle was missing, which is when he informed the police.
Through CCTV footage, the woman's involvement was proved and she was arrested, police said.