Some results of my grad research have been used in a recent paper, but I was not told. Should I do something about it?
You should have been cited, at least, if the old figures were used and you created them. There may even have been a copyright violation here as figures are sometimes (often?) considered to be a "complete" work for such purposes. 

You could ask for an explanation. You could express disappointment for the lack of acknowledgement. I can't predict the outcome, however. It might be an apology. It might be rage. What should happen is a correction, but that doesn't seem very likely. 

I'm assuming, of course, that the figures really were re-used, rather than just being similar and generated from the same data. 

But you have to judge whether to rock the boat a bit. It is your right to do so. If you need her as a source for your future advancement, then tread carefully.