Sorry Liz, I totally and strongly disagree with your response, but that's a good scenario, and you'll always get varying results depending on each person and their experiences. My response would be very similar to DavMen's (us 'draftys' must think alike

);
NEVER negotiate.....the reason being, what if you sacrificed the child, and the terrorist turns to you and asks you to grab the next child and do the same.....then the next, and next? "
You know for certain that she always keeps her word" This is a ridiculous statement to place in this scenario. Terrorists aren't the most 'trustworthy' bunch? Personally I'd prefer to be shot than to 'perhaps' survive knowing I took an innocent life to please a terrorist.
In my limited knowledge on terrorists, if they're wired with explosives, they've already made the conscious decision to end their own lives, and those around them, and no matter what they ask, that is the ultimate outcome they have ran through their minds over, and over, they are prepared for that.
Teachers aren't terrorist negotiators, that is a specialised skill in its own right, but the only option you would have would be to try to change the terrorist's views with sympathetic discussion, or distract them with some form of knowledgeable debate (I know, it's a risk, but better than becoming a 'tool' for their plight), by speaking with them, and stalling, it allows time for the 'police response-team' to gather the info they require, and do
their job.
In conclusion, I hope this never has to become a reality for yourself, or any teacher for that matter.....and as Elmo said, it's easy to speculate, but unless you're in that situation, you never know.
(sorry, I was going to go all 'McGyver' on it, but I guess you're after serious debate)