And "they" will have every "right" to treat her continuing employment in the light of the fact that she is not fully trained and qualified to do the work that is expected of her.
Seriously ... It seems to me that the best way through this problem is for her to follow all available informal channels and enter into sensible conversations aimed at finding a reasonable outcome. Climbing on to a legalistic hobby horse and exploring what the wording of the contract of employment means or doesn't mean is a recipe for unnecessary trouble.
Totally this.