S.R.
I could help some more if I knew what level she was teaching, but for lower level stuff, there are some good programs out there that are test/worksheet generators that have some graphs on them. The ones I used were from this website:
http://www.kutasoftware.com/
I have both the Pre-Algebra and the Algebra I
For higher levels (if she teaches high school calculus or college courses) you could look into these:
http://www.ptc.com/products/mathcad/ Program is called MathCad
http://www.wolfram.com/mathematica/ Program is called Mathematica
Personally, I either just used the Kuta Software to make coordinate planes or I drew my own for regular data charts.
I also occasionally used an online program called Study Island. It was a program that our school already had/paid for, and it has questions formatted like standardized tests for every state. You can tell it to make the questions fill-in-the-blank as well, and when you "create" a worksheet, it opens in Microsoft Word, & you can cut and paste into your own document. I think it requires some sort of paid subscription, but I have no idea how much it is.
I'll look around some more and see if I can find anything more useful!