Is it fair to my PhD student if I ask them to do "miscellaneous" work for a paper they're not going to be a coauthor of? I've started work as an assistant professor recently,
and my first PhD student has just started her first semester.

I'm working on a paper with my collaborators
which is almost ready to submit.
I am thinking of asking my PhD student
to help us in the writing of the paper
by drawing a graph using LaTeX/PGFPlots.
However, I am not sure if this is fair to her.
Here are how I see the pros and cons of giving this work to her.


Pros:
Offloading the drawing of the graph to her
would be beneficial to me because it would save my time.
In addition, she would be learning skills
that are useful in her academic career.
Indeed, I have used LaTeX and PGFPlots in my two most recent papers
and will almost certainly use it in the papers I write with my PhD student.
Cons:
I am afraid that she might feel taken advantage of,
in that I am offloading menial and tedious tasks to her,
asking her to do work for a paper
without allowing her to benefit by being a coauthor.
In our field (a type of applied mathematics),
the real work is doing math theory,
formulating problems, solving them or proving math results.
What I am asking her to do (drawing graphs)
is sometimes an important part of paper writing,
but not nearly as important as mathematically rigorous work
such as developing theory and proving math results.


Note: I estimate that it would take me 3-4 hours to draw the plot,
although it may take her a longer time (perhaps one or two days),
given that she is fairly new to using LaTeX/PGFPlots.



Thank you all for your answers and comments.
I posted what I decided to do as an answer below.
Preparing a graph from already-generated data, to me, doesn't merit co-authorship but would justify a mention in the Acknowledgements. However, something that takes two days out of a student's time (even if it would only take you 3-4 hours) seems like a lot to ask for just an acknowledgement. 

How useful is learning the process? If it's legitimately training that's important to her future career, that might tip the balance toward asking her to do it. However, I think my default would be to do it myself.

One other part of the equation (probably and hopefully only a very small part) is that the student is female, based on the pronouns in the question, and female scientists are often expected (from unexamined assumptions) to disproportionately look after administrative work.