New Manager, Potential New Employee

I’ve been the manager in a new company for a while now, and have been working on projects with an employee in another city. She’s expressed a desire to move to my city, so with the approval of her boss (my equal) invited her to come work with me directly for a few days. I had been impressed with her knowledge, but during the time she was here, she became kind of rowdy during a particularly stressful evening that we hadn’t expected to have to work so late. This kind of stressful work is common in our field, and I always reward them in some way, but only when the crisis is over. She was playfully throwing things in the computer room, and that red flagged me that she might not be able to handle the stress and may be on the childish side. This occurred a couple of times in the three days she was here. A couple of my employees were playing around with her, but I had no problem for an established trustworthy employee blowing off a little steam during a moment of downtime, although they all had a stern talking to about throwing things, even playfully, in the computer room. I did not single her out, but I suspect she knew she was on trial and should have been on her best behavior. If that was her best behavior, what would she be like when she’s comfortable? Was I wrong in not giving her the benefit of the doubt? Would you?