It is possible with cross contamination. You know touching themselves or someone besides you in the mouth, anal or groin area, and the touching you. It is also possible, but extremely rare to have  HSV 1 or 2 in the hand/foot.

That being said the risk of getting a STD is unbelievably low from getting a hand or foot job. I would not worry about it. I know of know no one that has caught an STD that way.

of fungus from a FJ.
I would also hope that her feet are smooth, lol.