A request in any way "No Beef" is automatically classified as a SPML - Special Meal.
So if you did request a special meal even though you had suggested that. However if you had told the crew upon boarding, they would have put something aside for you or at least let your mother choose her meal first.
Having said that, for 24left, VOML - Vegetarian Oriental Meal is always quite good on CX. You get a one of those crispy buns, and a vegetarian cooked Chinese style.