My employee is still nervous with me. What should I do?

I hired this person earlier this year. She is great at her job albeit a bit socially awkward. Its her first real job out of her grad school. One thing that really bothers me is that she seems always so stressed out during her weekly meeting with me. I think she is afraid of failure and getting fired, and the fact she supports an ill father seems to add to her mental duress. No one has been fired around here, and I certainly dont plan to fire her anytime soon because she does such specific tasks that we heavily depend on.

How should I approach this so that she feels more at..home?