Officers would like to speak to the woman in the CCTV image in connection with the incident, which occurred at 4.30pm on 30 January 2017.
Anyone who has any information is asked to contact police.
Dial 101, press 2 and ask to speak to PC 335 Robert Wardle.
Alternatively, Crimestoppers can be contacted anonymously on 0800 555 111.
Please quote reference number 12170033875 when passing on any information.