here is the question? how many of you have woken up and said "oops, guess i grew too much...didnt see that coming." if the workout is intense she's going to burn calories, is she's eating below or at maintenance, she'll get stronger, maybe eek out some muscle growth, but overall just have a tough workout.
as was said before, diet will dictate if she has the building blocks to grow from hard training, not training alone dictating whether she grows.
find something enjoyable thats challenging and not intimidating, you can get on with the real heavy stuff once form is established and confidence is gained.