Her parents had left early to arrive at the venue, but were in a car crash which meant they were delayed.
It features the same long sleeves, boat neck and form-fitting design as the Duchess of Sussex's £395k couture number.
The bride has been in a wheelchair for seven years after crushing her spine working as a gunner with the Royal Artillery.
The woman turned to Reddit for advice after a bridesmaid said she was being 'incredibly tacky'.
The Duke and Duchess of York's eldest daughter is due to walk down the aisle next year.