I was given such tasks by my adviser and I resented him for it. But, I think you should frame the thing differently. Make the student do the graph, and make a standard template they would use later in upcoming papers. That way some of their work will be useful for them, too.
If you want to be fair, you can explain the student what's in it for them, and tell them you understand if they don't do it. Or you could ask for the work as a favor.
I, personally, would do something else. If drawing that graph would help the student in the long run (they would learn how to do it with LaTeX/PGFPlots) they would have to do it. If it won't, I would ask for it as a favor and I'd be prepared for a refusal, which I wouldn't hold against her.
