I had a hernia in the upper portion of my intestinal tract that could have been problematic for my child's and my health if I had not done anything about it. My gastric surgeon said that it was best repaired in the second trimester, before my son grew into the area affected.
I decided to do the surgery under general anesthesia and both my son and I slept peacefully while they repaired the problem. We monitored heartbeats upon awaking and were just fine with no negative complications. My son and I were a little loopy with pain meds in recovery, but it was more important, in my opinion, to do the surgery than open the potential for an emergency surgery down the road in the last trimester.
Making the judgement call is the hard part and that's really personal to her type of hernia, situation, potential for crisis while pregnant, etc. The actual act of surgery and recovery is, professionally, not a difficult one.
I wish your daughter the best in her decision. Feel free to email me if you would like to learn more about my experience.