Police said the crash happened around 15:00 at the Parade, outside Bollywood Bytes by the junction of Cheapside.
Officers said the scale of the young woman’s injuries are “unknown” at this time.
They are now appealing for witnesses and want to speak to anyone who saw what happened or who may have dashcam footage.
Anyone who can help is asked to call 612612 or the independent charity Crimestoppers anonymously on 0800 555 111 or make a report via their anonymous online form at Crimestoppers-uk.org.