Debate is a preety thick topic.
I'd start reading here:
http://en.wikipedia.org/wiki/DebateThen contact your state Lawyers Association and keep asking. Check with whatever High School you think DD might attend, and have a long talk with the coach/teacher.
My son attended a 2 week, overnight, summer Debate camp as a rising 9th grader, because they have a 'Pre-novice' division, and he was 'too young' but not by much. According to him the begginers work 9am to 9pm 6 days a week. He felt that the other kids in the Pre-novice division were there because their parents pushed them, while the more experienced kids really loved debate.
So, after you figure out what kind of debate you want her to learn, you might have to start a middle school level club locally to you. (You middle school might already have something available)
At the high school level here, they are always looking for parents to act as judges, and they provide training. I've been doing that, and it's very touching. It might seem like a waste of time, but I'll bet your daughter could get involved with timekeeping or tabulation.
Best Wishes,
Grinity