So, my first M.S. student successfully defended her thesis today. She worked very hard and made some major progress on her abilities in the lab and writing department, and had a nice package of results with which to complete her MS degree. Her ideas and preliminary work have set the basis for a new direction for our group that got us a one-year internal pilot grant, and could turn out to be an interesting and fruitful direction for our technology. I'm really proud of her.
I also learned a lot about my role as a committee chair before and during a defense. Apparently I CAN jump in and guide the discussion, but I wasn't aware of that and kept my mouth shut at some points where I could have clarified or reworded the questions to help her understand what she was being asked, so our discussion got a little long and drawn out on some more general issues. Fortunately my two faculty mentors were on the committee, so they were able to give me some guidance on it afterwards for next time I have to help run someone's defense (hopefully not for a few more years once my going-into-second-year Ph.D. students get to that point!).